Search

Timing of pruning may affect wound susceptibility to wood-invading fungi, such as those associated with grapevine trunk diseases (GTDs). This study aimed to determine the effect of pruning time on natural fungal infection in six vineyards in Galicia, Spain, during two periods of three months each, from November to February and from February to May by ITS2 high-throughput amplicon sequencing. Fungal microbiome composition did not differ significantly with year of sampling. Pruned canes harboured a core community of fungal species, which appeared to be independent of the infection period. Accumulated rainfall over 8 and 11 weeks after pruning positively correlated with the total fungal microbiome. A seasonal effect on GTD fungal infection was detected for most genera, with a higher percent detected after pruning in February (winter) as compared with that of pruning in November (mid-autumn). Early pruning is recommended to reduce the infections caused by GTD fungi in Galicia., Funding was provided by Ministerstvo Školství, Mládeže a Tělovýchovy (CZ.02.1.01./0.0/0.0/16_017/0002334).

International audience; Botrytis cinerea and Neofusicoccum parvum are devastating fungal pathogens of grapevines. A total of 46 bacterial strains isolated from grapevines were screened for their antagonistic activity toward B. cinerea, which causes gray mold, and N. parvum, which causes cankers, trunk diseases and berry rot. In vivo screening using detached berries and leaf discs and in planta screening using growing grapevine cuttings were compared to select the most efficient biological control agents. On grapevine leaf discs, the most effective strain, Bacillus ginsengihumi, exhibited more than 80% antagonistic activity against the two major grapevine subpopulations of Botrytis cinerea (transposa and vacuma). At the berry surface, the efficacy of the bacterial strains strongly depended on the presence or absence of wounds. On stem cuttings, some strains, notably Pantoea agglomerans, were able to significantly reduce the length of the necrosis caused by N. parvum. Thus, both the plant parts and the pathogen species may significantly affect the efficacy of the bacterial strain. Marked differences between the two fungal pathogen species in terms of strain inhibitory efficacy were observed on wounded berries, as some Bacillus spp. strains efficiently controlled B. cinerea but not N. parvum. Noticeable differences in bacterial antagonist efficiencies were detected between berries and leaf discs inoculated with B. cinerea (transposa), e.g., some Paenibacillus spp. strains were efficient on leaves but not on berries. Synergistic relationships were also revealed between several bacterial strains and the pathogens. Some bacterial strains (e.g., Bacillus licheniformis) reduced B. cinerea rot severity in wounded and unwounded berries, but they increased N. parvum necrosis on stem cuttings.

Grapevine trunk diseases (GTDs) are the most widespread fungal diseases, affecting grapevines in all the major growing regions of the world, and their complete eradication is still not possible. Aiming to search alternatives to avoid the spread and high incidence of these diseases, the present work intended to molecularly identify the grapevine endophytic community, the phytopathogenic fungi associated with GTDs in vineyards within the Alentejo region, and to test potential antagonist microorganisms as biological control candidates against GTDs-associated fungi. Grapevine endophytic community showed a wide variety of fungi in GTDs&rsquo, asymptomatic and symptomatic plants, nine of them previously described as GTDs-associated fungi. GTDs prevalent fungi identified in symptomatic plants were Diaporthe sp., Neofusicoccum sp., and H. viticola. Almost all these fungi were also detected in asymptomatic plants, which shows the importance of investigating the interactions of fungal communities and confirms the need for early diagnosis of these diseases. Direct inhibition antagonism tests were performed among identified endophytes and GTDs phytopathogenic fungi, and all the endophyte fungi showed potential as biocontrol agents. Our findings suggest that endophytes are promising candidates for their use in biological control due to their antagonistic activity against the mycelia growth of some GTDs-associated fungi.

V okviru magistrskega dela smo želeli raziskati vpliv zdravstvenega stanja cepičev in petih različnih pripravkov za razkuževanje ter enega v kombinaciji s termoterapijo (TT) na vsebnost fenolnih spojin v kalusu cepljenk po siljenju in po klasiranju. V poskus smo vključili cepiče z zdravih (ZDR) ter asimptomatične (ASIM) in simptomatične (SIM) cepiče okužene z boleznimi lesa vinske trte (BLVT) iz trt sorte 'Cabernet Sauvignon'. Vse cepiče smo pred cepljenjem tretirali ločeno s pripravki Beltanol, Serenade, soda bikarbona, Remedier, BioAction ter kombinacijo Beltanola in TT. Po siljenju in po klasiranju smo glede na obravnavanje naključno izbrali 15 cepljenk, s katerih smo odvzeli kalus, iz katerega smo ekstrahirali in identificirali ter kvantificirali fenolne spojine. Potrdili smo, da zdravstveno stanje cepičev vpliva na različno vsebnost posameznih in skupnih fenolnih spojin v kalusu. Po siljenju smo značilno največjo vsebnost skupnih identificiranih fenolov (TAP 363-378 μg/g SM), flavanolov (FLA 297-310 μg/g SM) in stilbenov (STB 25,7-27,0 μg/g SM) izmerili v kalusu siljenk SIM in ZDR cepičev, po klasiranju pa vsebnost TAP, FLA in STB v kalusu cepljenk z ASIM cepiči. Po siljenju smo največjo vsebnost TAP (599-783 μg/g SM) izmerili v kalusu cepljenk z ZDR in SIM cepiči, razkuženih s pripravkom BioAction. Po klasiranju smo največjo vsebnost TAP (6951-7110 μg/g SM) izmerili v kalusu cepljenk z ASIM cepiči, tretiranih s pripravkoma Remedier in Beltanolom, pri ZDR cepičih (3231-3262 μg/g SM) z Remedier in soda bikarbono ter v kalusu s SIM cepiči (5024±40 μg/g SM), razkuženih s sodo bikarbono. Rezultati potrjujejo, da se cepljenka na cepljenem mestu (kalusu) različno odzove s sintezo fenolov na zdravstveno stanje cepiča ter uporabo pripravkov za razkuževanje zoper BLVT. The aim of this thesis was to determine how the sanitary status of the scions infected with grapevine trunk diseases (GTD) and five different disinfectants (one combinated with thermotherapy (TT)) impact on the phenolic content in callus of grapevine grafts after callusing and grading. The experiment included scions from healthy vines (ZDR), GTD infected asymptomatic vines (ASIM) and GTD infected symptomatic vines (SIM) of 'Cabernet Sauvignon' variety. All scions were treated separately with Beltanol, Serenade, sodium bicarbonate, Remedier, BioAction and with combination of Beltanol and TT. Callus from 15 grapevine grafts was sampled after callusing and grading. In callus individual and total analyzed phenolics (TAP) were identified and quantified. The results confirm that different sanitary status of scions (ZDR, ASIM and SIM) has an impact on the content of phenolic compounds in callus. After callusing the significantly highest content of TAP (363-378 μg/g FW), flavanols (FLA 297-310 μg/g FW) in stilbenes (STB 25,7-27,0 μg/g FW) in callus of SIM and ZDR scions was measured, while after grading the significantly highest content of TAP, FLA and STB was measured in callus of ASIM scions. After callusing the significantly highest content of TAP (599-783 μg/g FW) was measured in callus of ZDR and SIM scions, treated with BioAction. After grading the significantly highest content of TAP (6951-7110 μg/g FW) was measured in callus of ASIM scions, treated with Remedier in Beltanolom, in ZDR scions (3231-3262 μg/g FW) with Remedier in sodium bicarbonate and in SIM scions (5024±40 μg/g FW) with sodium bicarbonate. Results confirm sanitary status of grapevine scions and different disinfectants has an impact on phenolic content in callus od grapevine grafts.

Background DNA metabarcoding, commonly used in exploratory microbial ecology studies, is a promising method for the simultaneous in planta-detection of multiple pathogens associated with disease complexes, such as the grapevine trunk diseases. Profiling of pathogen communities associated with grapevine trunk diseases is particularly challenging, due to the presence within an individual wood lesion of multiple co-infecting trunk pathogens and other wood-colonizing fungi, which span a broad range of taxa in the fungal kingdom. As such, we designed metabarcoding primers, using as template the ribosomal internal transcribed spacer of grapevine trunk-associated ascomycete fungi (GTAA) and compared them to two universal primer widely used in microbial ecology. Results We first performed in silico simulations and then tested the primers by high-throughput amplicon sequencing of (i) multiple combinations of mock communities, (ii) time-course experiments with controlled inoculations, and (iii) diseased field samples from vineyards under natural levels of infection. All analyses showed that GTAA had greater affinity and sensitivity, compared to those of the universal primers. Importantly, with GTAA, profiling of mock communities and comparisons with shotgun-sequencing metagenomics of field samples gave an accurate representation of genera of important trunk pathogens, namely Phaeomoniella, Phaeoacremonium, and Eutypa, the abundances of which were over- or under-estimated with universal primers. Conclusions Overall, our findings not only demonstrate that DNA metabarcoding gives qualitatively and quantitatively accurate results when applied to grapevine trunk diseases, but also that primer customization and testing are crucial to ensure the validity of DNA metabarcoding results. Electronic supplementary material The online version of this article (10.1186/s12866-018-1343-0) contains supplementary material, which is available to authorized users.

Grapevine Trunk Diseases (GTDs), particularly esca, are major concerns in Spain. This study characterized the fungal and bacterial communities in a 30-year-old ‘Cabernet Sauvignon’ vineyard in Catalonia, Spain. Six symptomatic vines expressing esca-foliar symptoms and six additional asymptomatic plants were surveyed. Non-necrotic and necrotic tissues were sampled from rootstocks, trunks and cordons of the selected vines. Fungal isolations and molecular techniques were used in combination to investigate the endophytic microflora and to characterize the fungal and bacterial diversity of the vines. Pathogenic fungi involved in GTDs were identified and the associations were assessed between all the isolated fungal taxa and the health status of vines, host partsand tissue types. Phaeomoniella chlamydospora and Diplodia seriata were found in non-necrotic tissues, whereas Fomitiporia mediterranea was mainly found in soft-rot tissues, and Neofusicoccum parvum and Eutypa cf. lata in hard necrotic tissues. Several Alternaria and Trichoderma species were isolated, mainly from non-necrotic tissues. Thesingle strand conformation polymorphism fingerprinting method showed differences in bacterial and fungal communities between the different types of tissue in healthy and diseased vines. However, no differences were detected in these microbial communities between non-necrotic tissues from asymptomatic and symptomatic vines. Two frequently-isolated species of Paraconiothyrium were tested for pathogenicity, but their pathogenic roles ongrapevines was unclear. info:eu-repo/semantics/publishedVersion

National audience

Grapevines exhibiting general decline symptoms were observed in July 2012 in Arbatan, a region in Marand county, north-western Iran. Leaf necrosis symptoms were also observed in affected grapevines. Dark brown necrotic lesions and wood discoloration were observed in the vascular tissues of affected cordons. Fungal isolates, all with similar cultural and morphological features, were obtained from symptomatic tissues. Morphological characteristics indicated that the isolates were Macrophomina phaseolina. Sequence analysis of the elongation factor (EF-1α) gene from isolates confirmed this identification, with 100% similarity to the reference M. phaseolina sequences obtained from GenBank. Pathogenicity assays of two M. phaseolina isolates on 2-year-old potted vines (cv. ‘Keshmeshi’) demonstrated that M. phaseolina was pathogenic on grapevine. This study confirmed the association of M. phaseolina with grapevine decline symptoms, and represents the first report of this fungus associated with grapevine trunk diseases in Iran.

International audience; Esca is a widespread and damaging grapevine trunk disease in France. A survey was undertaken to identify relevant cultural factors that may influence symptom severity. Preliminary observations in the Aquitaine region confirmed the complex interactions among cultivar, vine training system, and climate, so the study was expanded to the national level to help account for esca in different wine growing regions. Twenty-five vineyard plots were examined. The plots were comparable by pairs, with the same cultivar (or cultivar with similar levels of susceptibility in a few cases), with the same age and similar soil and climatic environments, but with different training or pruning systems. Esca was the predominant trunk disease and prevalence was assessed by visible symptoms on leaves and on wood. Training systems with long arms (or cordons) were generally less affected by the disease than those with short or no arms. Pruning also played a major role, with a trend of less severe symptoms associated with less pruning. The study confirmed that foliar symptoms reveal the presence of the disease, but cannot be considered a reliable indicator of the disease impact in all situations. This study also confirmed: i) that vine training and pruning options may greatly influence the severity of esca, ii) that increasing the length of cordons may minimize the consequences of the wood necroses, and, iii) that simplifications of the woody vine structure (resulting from adoption of modern training and pruning options) may have favoured the development of esca.

[EN] Since the early 1990s, grapevine trunk diseases (GTDs) have posed threats for viticulture. Esca complex, Eutypa- and Botryosphaeria-diebacks, mostly detected in adult vineyards, are currently responsible for considerable economic losses in the main vine-growing areas of the world. Other GTDs, such as Petri- (Esca complex) and Black-foot diseases, are emerging problems in grapevine nurseries (resulting in grafting failures and/or loss of saleable plants) and in young vineyards. The impacts of GTDs in modern viticulture depend on several factors, some related to their complexity, and others linked to host plant characteristics, changes in vineyard management and to the scarcity of simple tools for their control. For these reasons control of GTDs remains difficult, also depending on knowledge transfer from research to field and vice versa. This paper outlines the main preventive and curative techniques currently applied, scientifically tested or not that have resulted from the outcomes of "Winetwork", a European Union funded project with special emphasis on the promising and innovative approaches.

There is evidence that secondary metabolites are involved in the fungal pathogenicity and virulence of Neofusicoccum spp. Fatty acids may also influence the plant&ndash, pathogen interaction but, so far, no information is available on their production by species of Neofusicoccum associated with Botryosphaeria dieback, which is a well-known syndrome of several plants with a complex etiology. In the present paper, the production of fatty acids in liquid medium, by strains of N. vitifusiforme and N. parvum associated with declining Sicilian vine plants, was evaluated. Data, acquired via gas chromatography&ndash, mass spectrometry (GC/MS), show the presence of linoleic acid as the most abundant fatty acid produced by both examined strains. In addition, the pathogenicity of N. vitifusiforme was tested on 2-year-old grapevine plants of cv. Inzolia.

International audience; Among grapevine diseases affecting European vineyards, Flavescence dorée (FD) and Grapevine Trunk Diseases (GTD) are probably the ones with the most severe economic consequences. UAV multispectral images could be a powerful tool for the automatic detection of symptomatic vines. But a missing key step consists of discriminating different kinds of diseases leading to similar leaf discoloration as it is the case with FD and GTD for red vine varieties. In this work we evaluate the potential of several indices to separate three types of vines in UAV multispectral images: asymptomatic, FD symptomatic and GTD (ESCA and Black Dead Arm) symptomatic. Ground truth data and UAV multispectral images have been acquired in 2016 over 21 selected vineyards covering 13 different varieties (red and white) over two areas in South of France. Fifteen vegetation indices and four biophysical parameters, among which three are linked to the leaf pigments content (chlorophyll, carotenoid and anthocyanin), were computed from UAV images. The potential of discrimination of these variables were evaluated using univariate classification approaches. Results are presented for red varieties vineyards. Best results were achieved with RGI and GRVI (based on the green and red spectral bands) and the Carotenoid biophysical parameter, which showed the best performance to discriminate healthy and symptomatic foliage. Nevertheless, some problems of FD and GTD pixels misclassification remain for all varieties, which limits the operationality of the method.

Hot water treatment (HWT) is used in nurseries to control pathogenic fungi involved in Grapevine Trunk Diseases (GTDs), as well as other pathogens, such as phytoplasmas. The long-term impact of this treatment on the entire microflora, especially on the general fungal microbiota living inside plants, still remains however unknown. In this study, the fungal microflora of vineyard plants, treated or not by HWT 14 and 15 years earlier were compared at different plant part levels. The fungal microflora was relatively abundant in the different types of wood tissues. Certain fungal genera were first isolated and then identified on the basis of their treatment or not by HWT. A significant change between 2010 and 2011, the two sampling years, was detected. Although the HWT may have affected the cuttings microflora at the nursery stage, this had not persisted after several years of HWT treatment for the fungi, especially the pathogenic ones. As HWT does not have a significant long-term control effect on GTD pathogens in mature plants in the vineyards, applying other sanitary methods as soon as HWT-young vines are planted in the vineyards is recommended.

Production of table grapes is a major export commodity in the region of Piura, one of the most important grape-production areas of Peru. Characteristic symptoms of Botryosphaeria dieback were observed in vineyards throughout this region. The aim of this study was to characterise the symptoms of dieback of table grapes; evaluate the incidence and prevalence of the disease; identify the aetiological agent and evaluate its pathogenicity and virulence. The disease was present in all vineyards surveyed but incidence varied with location. A botryosphaeriaceous fungus was isolated from symptomatic plants collected in five different vineyards in Piura. On the basis of morphological and cultural characters as well as phylogenetic analysis of the internal transcribed spacer region (ITS), and part of the translation elongation factor 1-α gene (EF1-α) the isolates were identified as belonging to the species Lasiodiplodia theobromae. Inoculation of cv. Red Globe plants confirmed the pathogenicity of the isolates and revealed differences in virulence among the isolates tested. This is the first report of L. theobromae as causal agent of dieback of table grapes in Peru, which represents a threat to Peruvian vineyards productivity and longevity.

In article number 1802315, Jochen Fischer, Frederik R. Wurm, and co‐workers report the first nanocarrier‐mediated drug delivery in plants. Enzyme‐degradable lignin nanocarriers are injected into the trunks of grapevine plants. They release a fungicide selectively inside of the plants and are able to cure the worldwide fungal plant disease Esca for the first time. This strategy will reduce the extensive spraying of pesticides in agriculture. Image credit: Katharina Maisenbacher.

Biological control of gray mold and grapevine trunk diseases (GTDs), which are major fungal diseases of grapevine, has a considerable potential development in the current context of reduction of chemical input in viticulture.The aim of this study was to select and study bacterial strains for antagonism against Botrytis cinerea, the causal agent of gray mold, and two key pathogens involved in GTDs: Phaeomoniella chlamydospora and Neofusicoccum parvum. The main screening experiments for antagonistic activity of 46 bacterial strains, isolated from Bordeaux vineyards, have been carried out under different in vivo and in planta conditions. The efficacy of protection by the antagonistic strains significantly depended on the bacterial strain, the targeted pathogen species, the host plant tissue or organ and, for N. parvum, also on the application mode of the bacterial strain and, for B. cinerea, on the transposon genotype: transposa or vacuma.A significant reduction in length of necrosis due to P. chlamydospora and/or N. parvum, ranging between 40 and 64% in non-grafted vine cuttings, resulted from three bacterial strains: Pantoea agglomerans (S1), Paenibacillus sp. (S19) and Bacillus pumilus (S32). These strains were thoroughly further investigated to determine their major modes of action by i) Antibiosis ii) production of antifungal volatile organic compounds, which have been identified, and/or iii) induction of different grapevine defense genes. Concerning B. cinerea, Enterobacter cowanii (S22), Enterobacter sp. (S23) Bacillus ginsengihumi (S38), Bacillus sp. (S43, S46) were of prime importance in the biocontrol by producing anti-Botrytis volatile and diffusible compounds or by competing for nutrients (case of E. cowanii S22).; Contre la pourriture grise et les maladies du bois (MdBs), qui sont des maladies cryptogamiques majeures de la vigne, la lutte biologique a un potentiel de développement considérable dans le contexte actuel de réduction des intrants chimiques en viticulture.L’objectif de cette thèse est de sélectionner et d'étudier des souches bactériennes antagonistes de Botrytis cinerea (Pourriture grise) et de deux champignons pathogènes clefs liés aux MdBs: Phaeomoniella chlamydospora et Neofusicoccum parvum. Les expériences de screening principales sont réalisées in vivo et in planta sur 46 souches bactériennes isolées dans le vignoble bordelais. Le niveau de protection par les souches antagonistes dépend significativement de la souche bactérienne, de l’espèce de champignon pathogène ciblée, du tissu ou organe végétal hôte, mais aussi pour N. parvum, du mode d’application de la souche bactérienne et, pour B. cinerea, du génotype lié aux transposons : transposa ou vacuma.Une réduction significative de 40 à 64% de la taille des nécroses dues à P. chlamydospora et/ou N. parvum est induite par trois souches bactériennes Pantoea agglomerans (S1), Paenibacillus sp. (S19) et Bacillus pumilus (S32) sur des boutures de vigne non greffées. Ces souches ont fait l'objet d'investigations approfondies pour déterminer leurs principaux modes d’action : Antibiose, production de composés volatils qui ont été identifiés et/ou induction de différents gènes de défense de la vigne.Concernant B. cinerea, les souches Enterobacter cowanii (S22), Enterobacter sp. (S23), Bacillus ginsengihumi (S38) et Bacillus sp. (S43, S46) présentent un pouvoir antagoniste important par production de composés volatils et diffusibles anti-Botrytis, ainsi que par compétition pour les nutriments par E. cowanii (S22).

Bolesti drva vinove loze, koje uzrokuju fitopatogene gljive sve više dobivaju na važnosti zbog značajnih šteta koje nanose vinovoj lozi. U Hrvatskoj postoji mali broj istraživanja bolesti drva vinove loze. Tijekom 2013., 2014. i 2015. godine sakupljeni su uzorci drva vinove loze iz 5 vinograda na lokalitetima koji su obuhvaćali Dalmaciju, Središnju Hrvatsku i Slavoniju a koji su pokazivali simptome koji se povezuju sa gljivičnim bolestima drva vinove loze. Iz uzoraka su dobivene čiste kulture gljiva te su grupirane prema svojim kulturalnim i morfološkim karakteristikama. Iz svake od navedenih grupa izolata, odabrani su reprezentativni izolati koji su podvrgnuti analizi molekularnim metodama s ciljem njihove identifikacije do razine vrste. Navedenim reprezentativnim izolatima izolirana je ukupna genomska DNA, te su metodom MSP-PCR, uporabom početnice M13 i korištenjem horizontalne gel elektroforeze, dobiveni DNA fingerprint profili. Na temelju analize navedenih DNA fingerprint profila, dio izolata bilo je moguće identificirati do razine vrste temeljem usporedbe njihovih DNA fingerprint profila s odgovarajućim profilima otprije identificiranih vrsta poznatih patogena drva vinove loze. Također, navedena analiza omogućila je provjeru pouzdanosti grupiranja izolata prema morfološkim karakteristikama, a unutar navedenih grupa, prema podudarnosti DNA fingerprint profila, bilo je moguće dodatno razlučiti podgrupe unutar kojih su odabrani reprezentativni izolati za daljnju identifikaciju na temelju molekularnih markera ITS i EF1-. Identifikacija izolata na temelju navedenih molekularnih markera provedena je metodom PCR korištenjem parova početnica ITS5/ITS4, odnosno EF728/EF986. Produkti PCR reakcije su sekvencirani, a dobivene DNA sekvence uspoređene su sa odgovarajućim sekvencama referentnih izolata u međunarodnoj banci gena GenBank korištenjem metode BLAST a po potrebi provedena i njihova filogenetska analiza. Na temelju dokaza dobivenih kombinacijom navedenih metoda, izolati su identificirani, a utvrđene su sljedeće vrste: Diplodia mutila, Botryosphaeria dothidea, Diplodia seriata, Phomopsis ampelina, Diaporthe eres, Sordaria fimicola, Valsa leucostoma, Schizophyllum commune, Stereum hirsutum, Kalmusia variispora. Grapevine trunk diseases caused by fungi are gaining importenance due to significant damage which thay inflict on grapevines. There is small number of researches on grapevine trunk diseases in Croatia. During 2013., 2014. and 2015. samples from five regions, encompassing Dalmatia, Central Croatia and Slavonia, whych exhibited simptoms associated with fungal grapevine trunk diseases, have been collected. From the samples, clean cultures of fungi have been obtained and grouped based on their cultural and morfological characteristics. From each of those groups, representative isolates have been chosen for analisis with molecular methods, and to be identified up to species level. From those representative isolates, complete genomic DNA has been isolated and with method MSP-PCR and primer M13, thrue visualisation by horizontal gel electrophoresis, DNA fingerprint profiles have been obtained. Based on analisis of those DNA fingerprint profiles, for part of isolates, identification up to the level of species was possible due to comparison of their DNA fingerprint profiles with adequate profiles already identified species of known grapevine trunk pathogens. Furthermore, mentioned analisis provided reliability check for grouping based on cultural nad morfological characteristics, and inside those groups, per compatibility of DNA fingerprint profiles, further distinction of subgroups was possible and inside whych representative isolates have been chosen for further identification based on molecular markers ITS and EF1-. Identification of isolates based on molecular markers has been conducted with method PCR by using pairs of primers ITS5/ITS4, or EF728/EF986. Products of PCR reaction have been sequenced and obtained DNA sequences have been compared to corresponding sequences of reference isolates in international gene bank GenBank with method BLAST and if neaded phylogenetic analisis. Based on evidence obtained in combination of mentioned method, isolates have been identified, those species were: Diplodia mutila, Botryosphaeria dothidea, Diplodia seriate, Phomopsis ampelina, Diaporthe eres, Sordaria fimicola, Valsa leucostoma, Schizophyllum commune, Stereum hirsutum, Kalmusia variispora.

Vineyards throughout the world, including Tunisia, are being attacked by Grapevine Trunk Diseases (GTDs) such as Esca and Botryosphaeriae dieback. In this study, the bacterial microflora colonizing the non-necrotic and necrotic wood tissues of Tunisian mature grapevines (cv Muscat d’Italie) was investigated. Both types of tissues were studied in order to decipher microbial communities associated with them and to find a suitable BCA that can be applied to the Tunisian terroir. Single-Strand Conformation Polymorphism (SSCP) analyses showed that complex bacterial communities specifically colonized both types of wood tissues. The 19 most abundant cultivable strains, selected on their morphology, were isolated from plant samples and assigned to Pantoea , Pseudomonas , Curtobacterium and Bacillus species based on the 16S rRNA and rpo B genes. Biochemical and microbiological screenings revealed that those 19 strains (i) metabolized differently carbon sources, even within the same species, (ii) possessed antibiotic genes, (iii) produced siderophores and solubilized phosphates and (iv) had an in vitro antagonistic effect against 3 fungal pathogens ( Lasidiodiplodia pseudotheobromae , Neofusicoccum parvum and Schizophyllum commune ) involved in GTDs. One strain, Bacillus subtilis “B6”, had a positive effect on young vines of a cultivar, Muscat d’Italie, frequently planted in Tunisia, by reducing the size of the wood necrosis caused by N. parvum , showing its potential to counteract infection caused by this GTDs agent .

International audience; In most vineyards worldwide, agents of grapevine trunk diseases represent a real threat for viticulture and are responsible for significant economic loss to the wine industry. The conventional microbiological isolation technique used to diagnose this disease is tedious and frequently leads to false negatives. Thus, a dire need exists for an alternative method to detect this disease. One possible way involves infrared spectroscopy, which is a rapid, nondestructive analytical tool that is commonly used for quality control of feed stuffs. In the present work, a midinfrared spectrometer was tested as a fast tool for detecting agents of grapevine trunk disease. Midinfrared spectra were collected from 70 Vitis vinifera L. cv. Cabernet-Sauvignon one year old trunk-wood samples that were infected naturally in one viticulture nursery of the south of France. The samples underwent polymerase chain reaction and morphological identification, and the results were correlated to the midinfrared spectra by using multivariate analysis to discriminate between noninfected and infected samples. Based on comparison with some control samples, the highest percentage of correct identification of fungal contamination when using the midinfrared spectroscopy method is 80%.

Flavescence dorée (FD) is a grapevine disease that spreads epidemically if not managed properly and implementation of control strategies is mandatory in most European winegrowing regions. Overall accepted strategies applied in FD management are based on vector monitoring, insecticide application and removal of infected vines and secondary hosts. Grapevine trunk diseases (GTD) involve a large number of xylem-inhabiting fungal species predominantly associated to botryosphaeria dieback, esca and eutypa dieback. Control strategies for GTD management are based on preventive techniques that minimize new infections. Both FD and GTD cause significant economic losses in European vineyards. Innovative practices and good management practices developed by scientists and winegrowers need to be disseminated and adapted to regular control strategies to maintain vineyard sustainability. Project WINETWORK is developing the innovation-driven methodology, which promotes the exchange of knowledge between science and practice. This network is implemented in ten winegrowing regions, within seven European countries. The methodology is built on a network of winegrowers and regional experts gathered in regional Technical Working Groups, Scientific Working Groups (one for each disease), and regional Facilitator Agents that stimulate their interaction. Bottom-up approach applied in WINETWORK includes surveys, conducted and synthesised by Facilitator Agents, to identify winegrower’s innovative practices, while scientists revise scientific data and adapt it to dissemination and practical use. Dissemination is adapted to different stakeholders and includes a summary of relevant practical and scientific knowledge available through the knowledge reservoir, newsletters, workshops, video clips, technical presentations, multimedia tools, etc. Overall objective of WINETWORK is to foster the exchange of scientific and practical knowledge to increase the productivity and sustainability of the sector and identify needs from the field and innovative solutions for future research agenda.

Grapevine trunk diseases (GTD) involve a large number of xylem-inhabiting fungal species mostly associated to botryosphaeria dieback, esca and eutypa dieback. Management of GTD is based on preventive control measures in order to minimize new infections and measures that reduce the existing fungal inoculum (vine removal, etc.). Flavescence dorée (FD) is a quarantine grapevine disease caused by a phytoplasma ‘Candidatus Phytoplasma vitis’ and spread by a Vitis specific vector, leafhopper Scaphoideus titanus Ball (Cicadellidae). Despite mandatory control measures FD is still a threat to the sustainability of European viticulture. Management of FD predominantly relies on the use of insecticides (vector control) and removal of infected vines and secondary hosts. Consequently, development of integrated approach in disease control is required. Both GTD and FD cause significant economic losses in European vineyards, referring to the necessity of finding alternative strategies to restrain their spread and negative impact on grape production. Project WINETWORK is developing the innovation-driven methodology based on multi-actor approach, which promotes the exchange of knowledge between science and practice in order to increase the productivity and sustainability of the sector and identify needs from the field and innovative solutions for future research agenda. This network is implemented in ten winegrowing regions, within seven European countries. The methodology is built on a network of winegrowers and regional experts gathered in ten regional Technical Working Groups, Scientific Working Groups (one for each disease), and regional Facilitator Agents that stimulate their interaction. Bottom-up approach applied in WINETWORK includes surveys, conducted and synthesised by Facilitator Agents, to identify winegrower’s innovative practices, while scientists revise scientific data and adapt it to dissemination and practical use. Dissemination is adapted to different stakeholders and includes a summary of relevant practical and scientific knowledge available through knowledge reservoir, newsletters, seminars, workshops, video lectures, technical presentations, etc. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No°652601.

A strain of Neofusicoccum parvum isolated from declining vines was pathogenic to grapevine cultivar Inzolia in Sicily. This strain produced some metabolites in liquid medium. Crude extract, through a bio-guided purification process, yielded four naphthalenone polyketides. They were identified by comparison with spectroscopic data and optical proprieties reported in literature as: (3S, 4S)-7-ethyl-3,4,8-trihydroxy-6-methoxy-3,4-dihydro-1-(2H)-naphthalenone, (3S*, 4S*)-3,4-dihydro-3,4,8-trihydroxy-7-(1-hydroxyethyl)-6-methoxy-1-(2H)-naphthalenone, (4S)-3,4-dihydro-4,8-dihydroxy-1-(2H)-naphthalenone, named botryosphaerones D and A, isosclerone, respectively, and (3S*,4S*)-3,4,5-trihydroxy-1-tetralone (1-4). Phytotoxic activity of the isolated compounds (1-4) was tested on grapevine leaves at using the leaf puncture assay. All tested compounds were phytotoxic, with botryosphaerone D showing the greatest activity. The phytotoxic effects decreased when treated leaves were exposed to light. All of the metabolites did not show in vitro antifungal activity against Diplodia seriata, Lasiodiplodia mediterranea, Neofusicoccum vitifusiforme, or Phytophthora citrophthora. This is the first report of in vitro production of botryosphaerones D and A, and 3,4,5-trihydroxy-1-tetralone by N. parvum.

Despite the high likelihood of infection and substantial yield losses from trunk diseases, many California practitioners wait to adopt field-tested, preventative practices (delayed pruning, double pruning, and application of pruning-wound protectants) until after disease symptoms appear in the vineyard at around 10 years old. We evaluate net benefits from adoption of these practices before symptoms appear in young Cabernet Sauvignon vineyards and after they become apparent in mature vineyards to identify economic hurdles to early adoption. We simulate production in five regions of California and find widespread benefits from early adoption, increasing vineyard profitable lifespans, in some cases, by more than 50%. However, hurdles to adopt may result from uncertainty about the cost and returns from adoption, labor constraints, long time lags in benefits from early adoption, growers’ perceived probabilities of infection, and their discount rate. The development of extension resources to communicate these benefits and potential hurdles to growers are likely to reduce uncertainty, leading to increased early adoption.