Characterization of Botrytis cinerea populations associated with treated and untreated cv. Moscato vineyards

Three Botrytis cinerea populations, isolated from three vineyards, one untreated and two treated twice a year, respectively, with fenhexamid or cyprodinil+fludioxonil, were investigated to evaluate the effect of repeated fungicide treatments on the presence and distribution of the transposons Boty and Flipper, and on the phenotypic traits of each pathogen community. The vacuma individuals lacking the two transposons represented the majority of the 390 B. cinerea isolates followed by transposa strains containing Boty and Flipper, while the remaining 67 isolates harboured respectively only Boty (60) or Flipper (7). This research has demonstrated that fungicide application did not influence the transposon distribution patterns, the sensitivity towards various botryticides, or the growth rate of the isolates belonging to the three different populations, but did induced overall reduction of the population size and selected isolates characterized by an enhanced pathogenicity, especially on Vitis vinifera leaves

Dissecting the susceptibility/resistance mechanism of Vitis vinifera for the future control of downy mildew

23CO.NA.VI. 2020 – 8° Convegno Nazionale di Viticoltura, Udine, Italy, July 5-7, 2021openInternationalBothThe Eurasian grapevine (Vitis vinifera), a species cultivated worldwide for high-quality wine production, is extremely susceptible to the agent of downy mildew, Plasmopara viticola. Nevertheless, germplasm from Georgia (Southern Caucasus, the first grapevine domestication centre), characterized by a high genetic variability, showed resistance traits to P. viticola. The cultivar Mgaloblishvili exhibited the most promising phenotype in terms of resistance against P. viticola. Its defence response results in: i) low disease intensity; ii) low sporulation; iii) damaged mycelium; iv) production of antimicrobial compounds such as volatile organic compounds (VOCs), whose effectiveness on the pathogen was evaluated by leafdisc assays. At the transcriptomic level, its resistance mechanism is determined by the differential expression of both resistance and susceptible genes. The resistance genes are related to: i) pathogen recognition through PAMP, DAMP and effector receptors; ii) ethylene signalling pathway; iii) synthesis of antimicrobial compounds (VOCs) and fungal wall degrading enzymes; iv) development of structural barriers (cell wall reinforcement). The first putative susceptible gene was the transcription factor VviLBDIf7 gene, whose validation was carried out by dsRNA (double-stranded RNA) assay. In this work, these unique results on plant-pathogen interaction are reviewed with the aim of developing new strategies to control the disease.openRicciardi, Valentina; Marcianò, Demetrio; Sargolzaei, Maryam; Marrone Fassolo, Elena; Fracassetti, Daniela; Brilli, Matteo; Moser, Mirko; Vahid, Shariati J.; Tavakole, Elahe; Maddalena, Giuliana; Passera, Alessandro; Casati, Paola; Pindo, Massimo; Cestaro, Alessandro; Costa, Alex; Bonza, Maria Cristina; Maghradze, David; Tirelli, Antonio; Failla, Osvaldo; Bianco, Piero Attilio; Quaglino, Fabio; Toffolatti, Silvia Laura; De Lorenzis, GabriellaRicciardi, V.; Marcianò, D.; Sargolzaei, M.; Marrone Fassolo, E.; Fracassetti, D.; Brilli, M.; Moser, M.; Vahid, S.J.; Tavakole, E.; Maddalena, G.; Passera, A.; Casati, P.; Pindo, M.; Cestaro, A.; Costa, A.; Bonza, M.C.; Maghradze, D.; Tirelli, A.; Failla, O.; Bianco, P.A.; Quaglino, F.; Toffolatti, S.L.; De Lorenzis, G

Methods for Fungicide Efficacy Screenings: Multiwell Testing Procedures for the Oomycetes <i>Phytophthora infestans</i> and <i>Pythium ultimum</i>

Oomycetes-borne diseases represent a serious problem for agriculture sustainability due to the high use of chemical products employed for their control. In recent years, increasing concerns on side effects associated with fungicide utilization have led to the reduction of the permissible modes of action, with the remaining ones continuously threatened by the increase of resistant strains in the pathogen populations. In this context, it is mandatory to develop new generation fungicides characterized by high specificity towards the target species and low environmental impact to guarantee the sustainability, productivity, and quality of food production. Fungicide discovery is a lengthy and costly process, and despite these urgent needs, poor description and formalization of high-throughput methodologies for screening the efficacy of active compounds are commonly reported for these kinds of organisms. In this study, a comprehensive picture of two high-throughput practices for efficient fungicide screening against plant-pathogenic oomycetes has been provided. Different protocols using multiwell plates were validated on approved crop protection products using Phytophthora infestans and Pythium ultimum as the model species. In addition, detailed statistical inputs useful for the analysis of data related to the efficacy of screenings are included

Editorial: Advances in grapevine genetic improvement: Towards high quality, sustainable grape production

Grapevine (Vitis vinifera ssp. vinifera) is the fruit crop with the largest economic value worldwide, considering its derived products. However, emerging climate change-derived threats along with established pathogens compromise the sustainability of traditional viticultural systems. Grapevine genetic improvement is critical to face this situation, as well as to adapt to novel market needs and regulatory frameworks. Current breeding and selection programs focus on the obtention and exploitation of cultivars combining high quality fruit traits, adequate yield, and some level of resistance to major biotic and abiotic stressors. To this aim, two main activities are conducted: (i) the screening of today’s standing Vitis diversity (Wolkovich et al., 2018), and (ii) the generation of individuals gathering favorable traits (Töpfer and Trapp, 2022). Among the tools facilitating the success of these activities, the identification of genotypes harboring favorable alleles, and the knowledge on the underlying genomic regions and gene variants is basic to speed up current and future grapevine improvement activitiesJT was funded by a Juan de la Cierva-Incorporación grant (IJC2018-035036-I)

Disease Forecasting for the Rational Management of Grapevine Mildews in the Chianti Bio-District (Tuscany)

Downy and powdery mildews are major grapevine diseases. In organic viticulture, a few fungicides with protectant activities (copper and sulphur in particular) can be used, and their preventative application frequently leads to unneeded spraying. The adoption of an epidemiological disease forecasting model could optimise the timing of treatments and achieve a good level of disease protection. In this study, the effectiveness of the EPI (Etat Potentiel d’Infection) model in predicting infection risk for downy and powdery mildews was evaluated in nine organic vineyards located in Panzano in Chianti (FI), over a 2-year period (2020–2021). The reliability of the EPI model was investigated by comparing the disease intensities, the number of fungicide sprayings, the quantities of the fungicides (kg/ha), and the costs of the treatment achieved, with or without the use of the model, in a vineyard. The results obtained over two seasons indicated that, in most cases, the use of the EPI model accurately signalled the infection risk and allowed for a reduction in the frequency and cost of spraying, particularly for powdery mildew control (−40% sprayings, −20% costs compared to the farmer’s schedule), without compromising crop protection. The use of the EPI model can, therefore, contribute to more-sustainable disease management in organic viticulture

Pathogen Adaptation to American (Rpv3-1) and Eurasian (Rpv29) Grapevine Loci Conferring Resistance to Downy Mildew

Durable resistance is a key objective in genetic improvement for disease resistance in grapevines, which must survive for years in the field in the presence of adaptable pathogen populations. In this study, the adaptation of 72 Northern Italian isolates of Plasmopara viticola, the downy mildew agent, has been investigated into Bianca, possessing Rpv3-1, the most frequently exploited resistance locus for genetic improvement, and Mgaloblishvili, a Vitis vinifera variety possessing the newly discovered Rpv29 locus. Infection parameters (latency period, infection frequency, and disease severity) and oospore production and viability were evaluated and compared to those of Pinot noir, the susceptible reference. The expected levels of disease control were achieved by both resistant cultivars (&gt;90% on Bianca; &gt;25% on Mgaloblishvili), despite the high frequency of isolates able to grow on one (28%) or both (46%) accessions. The disease incidence and severity were limited by both resistant cultivars and the strains able to grow on resistant accessions showed signatures of fitness penalties (reduced virulence, infection frequency, and oospore density). Together, these results indicate an adequate pathogen control but suitable practices must be adopted in the field to prevent the diffusion of the partially adapted P. viticola strains to protect resistance genes from erosion

Influence of Nitrogen on Grapevine Susceptibility to Downy Mildew

Downy mildew, caused by the obligate parasite Plasmopara viticola, is one of the most important threats to viticulture. The exploitation of resistant and susceptibility traits of grapevine is one of the most promising ways to increase the sustainability of disease management. Nitrogen (N) fertilization is known for influencing disease severity in the open field, but no information is available on its effect on plant-pathogen interaction. A previous RNAseq study showed that several genes of N metabolism are differentially regulated in grapevine upon P. viticola inoculation, and could be involved in susceptibility or resistance to the pathogen. The aim of this study was to evaluate if N fertilization influences: (i) the foliar leaf content and photosynthetic activity of the plant, (ii) P. viticola infectivity, and (iii) the expression of the candidate susceptibility/resistance genes. Results showed that N level positively correlated with P. viticola infectivity, confirming that particular attention should be taken in vineyard to the fertilization, but did not influence the expression of the candidate genes. Therefore, these genes are manipulated by the pathogen and can be exploited for developing new, environmentally friendly disease management tools, such as dsRNAs, to silence the susceptibility genes or breeding for resistance

Assessing suffering of patients on cancer treatment and of those no longer treated using ESAS-Total Care (TC)

Aim: The aim of the study was to assess the suffering of patients on oncologic treatment and of those no longer on treatment. Preliminarily, we aimed to confirm the psychometric properties of Edmonton Symptom Assessment System-Total Care (ESAS-TC) in different stages of the disease. The ESAS-TC screens physical and psychological symptoms, but also spiritual pain, discomfort deriving from financial problems associated with illness, and suffering related to social isolation. Methods: A sample of consecutive advanced cancer patients on oncologic therapies treated at the Internistic and Geriatric Supportive Care Unit (IGSCU) of Istituto Nazionale dei Tumori, Milano, and of terminal patients no longer on treatment and cared for by the Fondazione ANT palliative home care team were asked to fill the ESAS-TC. In order to strengthen the previous validation study of the ESAS-TC, 3-ULS (to assess social isolation), JSWBS (to assess spiritual well-being), COST-IT (to assess financial distress), and KPS (to assess functional status) were administered too. Results: The questionnaires were self-reported by 108 patients on treatment (52% >60 years old, female 53%, and 61% with KPS 90-100) and by 94 home care patients (71% >60 years old, female 51%, and 68% with KPS 10-50). The sound psychometric characteristics of ESAS-TC were confirmed. Patients on treatment showed lower total ESAS-TC score (19.3 vs 52.7, p<.001) after controlling for age and functional status, and lower financial distress (p.<001). Financial distress, spiritual suffering, and social isolation, after controlling for age, showed a significantly higher score in home care patients. Conclusions: Only through an adequate routine assessment with validated tools is it possible to detect total suffering, the "Total pain" of patients, and treat it through a multidisciplinary approach. The study confirms the reliability and validity of the Italian version of ESAS-TC and the importance of supportive and early palliative care fully integrated with oncological treatment