Fungicides and the grapevine wood mycobiome: a case study on Tracheomycotic Ascomycete Phaemoniella chlamydospora reveals potential for two novel control strategies

Original ResearchPhaeomoniella chlamydospora is a tracheomycotic fungus that colonizes the xylem of grapevines (Vitis vinifera L.), causing wood discoloration, brown wood streaking, gummosis, and wood necrosis, which negatively affect the overall health, productivity, and life span of vines. Current control strategies to prevent or cope with P. chlamydospora infections are frequently ineffective. Moreover, it is unclear how fungicides commonly applied in vineyards against downy and powdery mildew agents affect the wood mycobiome, including wood pathogens such as P. chlamydospora. In this study, we used next-generation sequencing to assess the effects of foliar spray of grapevines with inorganic (copper oxychloride and sulfur), synthetic (penconazole and fosetyl-aluminum), and natural (Blad) fungicides currently used against the downy and powdery mildews. The subjects of our investigation were (i) the resident wood mycobiome, (ii) the early colonization by a consortium of fungal wood endophytes (ACEA1), (iii) the wood colonization success of P. chlamydospora, and (iv) the in planta interaction between P. chlamydospora and ACEA1, under greenhouse conditions, in rooted grapevine cuttings of cv. Cabernet Sauvignon. The data obtained suggest that the resident mycobiome is affected by different fungicide treatments. In addition, the early colonization success of the endophytes composing ACEA1 varied in response to fungicides, with relative abundances of some taxa being overrepresented or underrepresented when compared with the control. The wood colonization by P. chlamydospora comported significant changes in the mycobiome composition, and in addition, it was greatly affected by the foliar spray with Blad, which decreased the relative abundance of this pathogen 12-fold (4.9%) when compared with the control (60.7%) and other treatments. The presence of the pathogen also decreased considerably when co-inoculated into the plant with ACEA1, reaching relative abundances between 13.9% and 2.0%, depending on the fungicide treatment applied. This study shows that fungicides sprayed to prevent infections of powdery and downy mildews have an control strategies to fight P. chlamydospora, namely, the foliar spray with Blad and the use of ACEA1. Further studies to confirm these results are requiredinfo:eu-repo/semantics/publishedVersio

LE CORBUSIER’S APARTMENT-STUDIO : 3D MODEL DATA OF PRELIMINARY RESEARCH FOR THE RESTORATION

Fondation Le Corbusier and A-BIME have collaborated to collect, analyse and organize preliminary research data for the restoration of the Le Corbusier’s apartment-studio in Paris using a methodology based in a 3D model. This work, developed by A-BIME since 2014, has been financed by Fondation Le Corbusier thanks to a “Keeping it modern Grant”, giving by the Getty Foundation. The aim is to have faster and easier access to various data of the building by using a clear and documented digital graphic document.For each step, the archives provided by the architect and the companies have been studied to understand and know the nature and quality of materials, technical arrangements and their on-site implementation. A study on technical installations and isolation as be provided as well by investigation in the apartment. By switching between the documents and the images, the know-how increases along with the development of the 3D model; the architectural elements have been drawn and modelled from the archive data and from the survey and diagnostic phase.The numerical construction, based on precast elements, follows the pioneering efforts of specialized architects with the BIM (Building Information Model) technology. Thanks to the .IFC format the model has been imported in several software in order to proceed structural and hydrothermal simulations. The results have been used has guidelines by the Fondation Le Corbusier to forecast the consequences of restoration choices.</p

Cultivar Susceptibility to Natural Infections Caused by Fungal Grapevine Trunk Pathogens in La Mancha Designation of Origin (Spain)

[EN] Grapevine trunk diseases (GTDs) are one of the main biotic stress factors affecting this crop. The use of tolerant grapevine cultivars would be an interesting and sustainable alternative strategy to control GTDs. To date, most studies about cultivar susceptibility have been conducted under controlled conditions, and little information is available about tolerance to natural infections caused by GTD fungi. The objectives of this study were: (i) to identify tolerant cultivars to GTD fungi within a Spanish germplasm collection, based on external symptoms observed in the vineyard; and (ii) to characterize the pathogenic mycoflora associated with symptomatic vines. For this purpose, a grapevine germplasm collection including 22 white and 25 red cultivars was monitored along three growing seasons, and their susceptibility for esca foliar symptoms was assessed. Fungi were identified by using morphological and molecular methods. Cultivars such as, 'Monastrell', 'Graciano', 'Cabernet Franc', 'Cabernet Sauvignon', 'Syrah', 'Moscatel de Alejandria', 'Sauvignon Blanc', and 'Airen' displayed high susceptibility to GTDs, whereas others such as 'Petit Verdot', 'Pinot Noir', 'Chardonnay', and 'Riesling' were considered as tolerant. The prevalent fungal species isolated from symptomatic vines were Phaeomoniella chlamydospora (27.9% of the fungal isolates), Cryptovalsa ampelina (24.6%), and Dothiorella sarmentorum (21.3%).This research was founded by FEDER funding through a State Program of I+D+i oriented to the Challenges of Society (RTA2015-00015-C02-00), supported by The National Institute for Agricultural and Food Research and Technology (INIA). D.G. and J.M. were supported by the Ramon y Cajal program, Spanish Government (RyC-2017-23098 and RyC-028404).Chacón-Vozmediano, JL.; Gramaje, D.; León Santana, M.; Armengol Fortí, J.; Moral, J.; Izquierdo-Cañas, PM.; Martínez-Gascueña, J. (2021). Cultivar Susceptibility to Natural Infections Caused by Fungal Grapevine Trunk Pathogens in La Mancha Designation of Origin (Spain). Plants. 10(6):1-14. https://doi.org/10.3390/plants10061171S11410

Importance of quality maintenance pruning for young Ugni Blanc grapevines

This article investigates and models the effects of maintenance pruning quality on the initial formation of desiccation cones and wood necrotisation. Two different types of pruning, short and long pruning cuts, were performed annually for three years in two Charente vineyards. The short pruning type removed the diaphragm. In the long one, four modalities were applied: these ranged from keeping a 1 cm chicot above the diaphragm, to leaving a much longer one to preserve the bud. Neither of the trials, whether for short or long pruning, showed any correlation between necrosis length and spur diameter (R2 < 0.14 for both trials). Charente Ugni Blanc necrosis length, for long pruning, proved significantly more extensive 8 months after pruning, without damaging the diaphragm. Chicot necrotisation rates varied with each vintage, particularly in 2020, the year immediately following the first maintenance pruning. When long pruning cuts preserved 2–3 cm of cane above the diaphragm, the desiccation cones were blocked, leaving the sap flow unimpeded. © 2024, International Viticulture and Enology Society. All rights reserved

Influence of curettage on Esca-diseased Vitis vinifera L. cv. Sauvignon blanc plants on the quality of musts and wines

Aim: A study on Sauvignon blanc (SB) cultivar in France showed that curettage had an effect on the resilience of GTD grapevines. No experiments, however, have been conducted on its effects on wine quality, particularly on white Sauvignon blanc cultivar wines. Methods and results: Grapevines from Sauvignon blanc cultivar that had expressed Esca-foliar symptoms were used for the study, with some of them having been curetted in 2014. Subsequently, bunches from Control (asymptomatic), Curetted and Esca-symptomatic vines were harvested in 2017 and 2018 in order to produce white wine. Technical and chemical results on both must and wine showed that wines from curetted plants were similar to those from asymptomatic vines. There were differences, however, for Esca-diseased vines, where the alcoholic fermentation of musts was faster than for the other modalities. Olfactometry results showed that, for the one-year-old 2017 vintage wines, no differences were detected, although they were for the 2018 vintage. Conclusion: The results of the chemical analyses and wine tasting showed that the wines from curetted and asymptomatic grapevines were similar, and that their quality was the same. Significance of the study: The quality of wines from curetted vines compared to asymptomatic ones was confirmed and validated through chemical and sensory analyses of the must and the one-year-old wines

Characterization of the wood mycobiome of Vitis vinifera in a vineyard affected by Esca. Spatial distribution of fungal communities and their putative relation with leaf symptoms

Original ResearchEsca is a disease complex belonging to the grapevine trunk diseases cluster. It comprises five syndromes, three main fungal pathogenic agents and several symptoms, both internal (i.e., affecting woody tissue) and external (e.g., affecting leaves and bunches). The etiology and epidemiology of this disease complex remain, in part, unclear. Some of the points that are still under discussion concern the sudden rise in disease incidence, the simultaneous presence of multiple wood pathogens in affected grapevines, the causal agents and the discontinuity in time of leaf symptoms manifestation. The standard approach to the study of esca has been mostly through culture-dependent studies, yet, leaving many questions unanswered. In this study, we used Illumina R next-generation amplicon sequencing to investigate the mycobiome of grapevines wood in a vineyard with history of esca. We characterized the wood mycobiome composition, investigated the spatial dynamics of the fungal communities in different areas of the stem and in canes, and assessed the putative link between mycobiome and leaf symptoms. An unprecedented diversity of fungi is presented (289 taxa), including five genera reported for the first time in association with grapevines wood (Debaryomyces, Trematosphaeria, Biatriospora, Lopadostoma, and Malassezia) and numerous hitherto unreported species. Esca-associated fungi Phaeomoniella chlamydospora and Fomitiporia sp. dominate the fungal community, and numerous other fungi associated with wood syndromes are also encountered (e.g., Eutypa spp., Inonotus hispidus). The spatial analysis revealed differences in diversity, evenness and taxa abundances, the unique presence of certain fungi in specific areas of the plants, and tissue specificity. Lastly, the mycobiome composition of the woody tissue in proximity to leaves manifesting ‘tiger stripes’ symptoms of esca, as well as in leaf-symptomatic canes, was highly similar to that of plants not exhibiting any leaf symptomatology. This observation supports the current understanding that leaf symptoms are not directly linked with the fungal communities in the wood. This work builds to the understanding of the microbial ecology of the grapevines wood, offering insights and a critical view on the current knowledge of the etiology of escainfo:eu-repo/semantics/publishedVersio

Overview of grapevine trunk diseases in France in the 2000s

The National Grapevine Trunk Disease Survey was conducted in France from 2003 to 2008 to monitor grapevine trunk diseases (GTDs), eutypa dieback and esca/black dead arm (BDA). Data collected from seven regions, 329 vineyards and 12 cultivars were analysed. There were great variations amongst regions in the incidence of GTDs. For esca/BDA, two groups were distinguished: vineyards in Jura and Charentes had greater incidence (93–95%) than those of Bordeaux, Alsace and Bourgogne (54–82%). Incidence increased in Charentes over the 6-year survey, with the highest values being recorded during the last 2 years. For eutypa dieback, all vineyards of Charentes were affected, with 17 to 25% of vines expressing symptoms; for the other regions, 52 to 80% of vineyards were affected, with incidences below 3%. Cultivars Savagnin and Trousseau in Jura were especially affected by esca/BDA. Instead, Ugni Blanc in Charentes was most affected by eutypa dieback. One cultivar could be significantly more affected in one region than in another. The global health status of the vineyards was also investigated. (i) For four regions, 82% (Jura) to 87% (Alsace) of the grapevines were healthy, but this percentage decreased steadily (67%) in Charentes. (ii) Plants infected by GTDs were 32 and 18% in Jura and Charentes respectively, and only 2.9% in the Bourgogne region. (iii) The unproductive plants, i.e. dead, missing, replanted or restored, represented a significant part of the losses (6.6% in Charentes to 9.9% in Jura). The extension of GTDs is discussed with regard to the abiotic and biotic factors that may favour the diseases

Recovery after curettage of grapevines with esca leaf symptoms

Grapevine curettage was re-introduced in France in the early 2000s, and is important for facilitating recovery of plants from esca disease. This surgical practice involves removal of deadwood of vines with leaf symptoms, focusing on white rot generally observed at the centres of grapevine trunks. Assessment of the efficacy of this practice was initiated in the Bordeaux region in 2014. One ‘Sauvignon Blanc’ vineyard severely affected by esca was initially surveyed in the summer of 2014, to identify and treat vines with esca foliar symptoms. Annually thereafter, from 2014 to 2018, selected vine stocks were curetted. Two other ‘Sauvignon Blanc’ vineyards also displaying high levels of esca damage were added to the study in 2015 and 2016. Curettage treatments ceased in 2018, resulting in 11 trials (vineyard × year combinations). In total, 856 vines (422 curetted and 434 control vines) were then surveyed annually up to 2021, for assessments and comparisons of esca development. At each site, plants with esca symptoms recovered well after curettage : on average 85% of all curetted vines became asymptomatic the year immediately after the treatment. Six years after treatment, for curettage campaigns carried out in 2014 and 2015, more than half of the curetted vines were symptom-free, whereas <12% of the control vines were asymptomatic, and gradual loss of efficacy was observed at each site. The mean annual proportion of efficacy erosion was approx. 8% per year. This study highlights the possible short- and midterm benefits of trunk surgery to enable recovery of esca-affected vines, and for them to recover and remain leaf-asymptomatic for several years

Overview of grapevine trunk diseases in France in the 2000s

The National Grapevine Trunk Disease Survey was conducted in France from 2003 to 2008 to monitor grapevine trunk diseases (GTDs), eutypa dieback and esca/black dead arm (BDA). Data collected from seven regions, 329 vineyards and 12 cultivars were analysed. There were great variations amongst regions in the incidence of GTDs. For esca/BDA, two groups were distinguished: vineyards in Jura and Charentes had greater incidence (93–95%) than those of Bordeaux, Alsace and Bourgogne (54–82%). Incidence increased in Charentes over the 6-year survey, with the highest values being recorded during the last 2 years. For eutypa dieback, all vineyards of Charentes were affected, with 17 to 25% of vines expressing symptoms; for the other regions, 52 to 80% of vineyards were affected, with incidences below 3%. Cultivars Savagnin and Trousseau in Jura were especially affected by esca/BDA. Instead, Ugni Blanc in Charentes was most affected by eutypa dieback. One cultivar could be significantly more affected in one region than in another. The global health status of the vineyards was also investigated. (i) For four regions, 82% (Jura) to 87% (Alsace) of the grapevines were healthy, but this percentage decreased steadily (67%) in Charentes. (ii) Plants infected by GTDs were 32 and 18% in Jura and Charentes respectively, and only 2.9% in the Bourgogne region. (iii) The unproductive plants, i.e. dead, missing, replanted or restored, represented a significant part of the losses (6.6% in Charentes to 9.9% in Jura). The extension of GTDs is discussed with regard to the abiotic and biotic factors that may favour the diseases