Wine Cultivars Research Articles

Quantitative Proteomics Analysis of ABA- and GA3-Treated Malbec Berries Reveals Insights into H2O2 Scavenging and Anthocyanin Dynamics.

Abscisic acid (ABA) and gibberellic acid (GA3) are regulators of fruit color and sugar levels, and the application of these hormones is a common practice in commercial vineyards dedicated to the production of table grapes. However, the effects of exogenous ABA and GA3 on wine cultivars remain unclear. We investigated the impact of ABA and GA3 application on Malbec grapevine berries across three developmental stages. We found similar patterns of berry total anthocyanin accumulation induced by both treatments, closely associated with berry H2O2 levels. Quantitative proteomics from berry skins revealed that ABA and GA3 positively modulated antioxidant defense proteins, mitigating H2O2. Consequently, proteins involved in phenylpropanoid biosynthesis were downregulated, leading to decreased anthocyanin content at the almost ripe stage, particularly petunidin-3-G and peonidin-3-G. Additionally, we noted increased levels of the non-anthocyanins E-viniferin and quercetin in the treated berries, which may enhance H2O2 scavenging at the almost ripe stage. Using a linear mixed-effects model, we found statistical significance for fixed effects including the berry H2O2 and sugar contents, demonstrating their roles in anthocyanin accumulation. In conclusion, our findings suggest a common molecular mechanism by which ABA and GA3 influence berry H2O2 content, ultimately impacting anthocyanin dynamics during ripening.

The Influence of Prefermentation Skin Contact, Stabulation, and Skin Fermentation on the Aromatic Behaviour and Phenolic Compounds of Important Austrian White Wine Cultivars

Many varietal aromas of wine are located in the berry skin. In the present study, we evaluated four important Austrian grape varieties: Grüner Veltliner, Sauvignon Blanc, Traminer, and Pinot Blanc. We assessed whether prefermentation skin contact, fermentation with the skin (only for Grüner Veltliner), and stabulation (lees stirring; only for Sauvignon Blanc, Traminer, and Pinot Blanc) could enhance the varietal aromas of the different grape cultivars. The aim was to intensify the varietal aromas without extracting the undesirable phenols. We performed a detailed analytical characterisation of approximately 100 volatile and phenolic compounds as well as a sensory characterisation. Although mash fermentation significantly increased the spicy aromas of Grüner Veltliner, which are affected by climate change (especially the sesquiterpene rotundone), it markedly decreased the fruitiness and increased the bitterness; therefore, it cannot be recommended for this cultivar. For Sauvignon Blanc, stabulation is a possible option; the varietal aromas (thiols and methoxypyrazines) were increased in the final wines of these variants. For Pinot Blanc and Traminer, prefermentation skin contact yielded the best results: for Traminer, it produced the highest content of monoterpenes (especially z-rose oxide), and for Pinot Blanc, it produced the highest content of ethyl esters. To summarise, stabulation will not completely replace classic skin contact, and mash fermentation is certainly not an alternative for the production of standard Grüner Veltliner wine. However, additional investigations are necessary with regard to other grape varieties, terroirs, and vintages before we can make final recommendations.

New problems for old vineyards: Mitigating the impacts of yellow-legged hornets (Vespa velutina) in a historical wine-producing area

Traditional small-sized vineyards are especially sensitive to different impacts, including the arrival of new pests. The adults of the yellow-legged hornet (Vespa velutina), an invasive alien species present in the Iberian Peninsula since 2010, feed on sugary foods, causing crop losses in vineyards. However, present management techniques for the control of V. velutina are limited, and they do not provide effective control in agricultural settings. This work aims to evaluate the use of an exclusion system in a traditional non-mechanized vineyard of a highly invaded area by V. velutina in NW Spain (Protected Geographical Indication of Betanzos, Galicia) as a method to mitigate the damage caused by hornets. Anti-hail nets were used in a factorial design experiment with groups of netted and unnetted vines of two white wine cultivars in order to address the vineyard production loss. In particular, we aim to 1) asses the effectiveness of anti-hail netting on preventing grape yield loss, 2) assess the impact of anti-hail netting on grape ripening and incidence of bunch fungal infection, and 3) study the potential relationship between the damage caused by V. velutina and grape fungal diseases. Results show that the tested exclusion system increases the crop yield, since it prevents effectively both the damage caused by hornets and birds. No significant correlation between the damage caused by V. velutina and the incidence of bunch fungal diseases was found in either cultivar. However, netting increased slightly the final sugar content in one of the cultivars, as well as the incidence of bunch fungal damage. We discuss the management implications of this exclusion method within the framework of agricultural land abandonment and the loss of traditional landscapes.

Preliminary characterization of chemical and sensory attributes for grapes and wines of different cultivars from the Weibei Plateau region in China

Chemical and sensory attributes play a vital role in evaluating the quality of grapes and wines. This study compared basic physicochemical parameters, organic acids, phenolic compounds, and aroma profiles of grapes and wines of six cultivars using chemometrics. The results showed that the reducing sugar contents of Beibinghong, Gongniang, and Granoir grapes were significantly higher than those of others cultivars, whereas their juice yields were significantly lower. The phenolic compound contents in Moldova, Beibinghong, and Gongniang grape skins and wines were higher than those in others cultivars. The organic acid contents in Beibinghong grape and Dunkelfelder wine were highest. Beibinghong and Gongniang grapes and wines showed richer aldehyde and ester concentrations. Beibinghong wine obtained the highest sensory scores. Ethyl decanoate, coumaric acid, and methyl dodecanoate were characteristic variables distinguishing wine cultivars, exhibiting important contributions to their sensory characteristics. These findings were useful for viticulturists and winemakers to select grape varieties.

Optimization of a Simple Analytical Workflow to Characterize the Phenolic Fraction from Grape Pomace

The recovery of polyphenols from grape pomace (GP) supports the promotion of sustainable bioeconomy. Accordingly, the development of pre-treatment and extraction techniques using low-solvent amounts and energy-efficient processes is highly desirable. In this work, a comprehensive strategy to maximize phenol extraction from two Umbrian red wine cultivars, Cabernet Sauvignon and Merlot, was proposed. Focus was paid to sample pre- (fresh, air-, oven- and freeze-dried pomace) and post-extraction (chemical- and enzymatic-hydrolysis) treatments. An experimental design was applied to optimize phenol recovery by ultrasound-assisted extraction: the variables water content in ethanol (20–80% v/v) and time (10–30 min) highlighted a critical influence on the total phenol content (TPC) selected as the response. β-glucuronidase hydrolysis provided the highest TPC and in vitro total antioxidant capacity also improving phenol identification and quantification via HPLC–DAD (particularly evident for freeze-dried Merlot and Cabernet GP, which gave a total phenolic content measured by HPLC equal to 1904.08 mg/g and 2064.64 mg/g, respectively). LC-HRMS/MS analysis allowed identity confirmation of the major phenols, and cytotoxicity assay highlighted the safety of the selected β-glucuronidase extracts towards Caco2 cell line. Ultimately, in the present work, we have addressed the importance of the recovery of bioactive compounds from grape pomace by proposing a comprehensive analytical strategy in which different methodological alternatives have been evaluated to preserve these compounds, in a frame of sustainability on a larger industrial scale.

Comparison of Conventional and Organic Wines Produced in Kutnohorsk Region (Czech Republic)

A healthy lifestyle and environmental protection play a big role in today’s modern society. The production of organic wine, as with other organic commodities, is therefore becoming increasingly popular with consumers. The selling price of organic wine is higher than that of wine that is not declared organic or BIO, so the question arises from consumers as to whether these wines contain more bioactive compounds and substances beneficial to the body. From a general point of view, it is known that grapevines contain a wide range of natural phenols and polyphenols. These substances affect the sensory properties of wines, especially color and taste. The most phenolic substances are found in red wines, slightly less in orange wines, and the lowest amounts are found in white wines. However, the representation of individual substances and their ratios differs based on the varieties and age of the wines. Therefore, this study aimed to compare the profile (chemical, physical, and sensory) of organic wines compared to wines created from nonorganic grapes, which are grown in a selected wine region—Kutná Hora. The analyzed wines were created from the same grape wine cultivar in the Kutná Hora area. The following analyses were performed on the wine samples: the phenolic and antioxidant profiles, the content of sulfites (free and total), alcohol, sugars, vitamins, density determination, and also sensory evaluation. The present study showed exact differences between samples of wines produced from the same cultivar and the same region, but declared as organic wines and wines from conventional production. Although a higher number of bioactive substances is expected in wines from organic production, in most cases it did not show a statistically significant difference in the sense of a higher amount in BIO wines; on the contrary, in many cases, the content of these substances was higher in wines from integrated production.

Dinâmica populacional de Drosophila suzukii em vinhedo e susceptibilidade de cultivares viníferas

Abstract Grapes are not considered a good host for the spotted-wing drosophila, Drosophila suzukiiHowever, its damage results in qualitative and quantitative losses to the wine grapes berries. Knowing the D. suzukii population dynamics in vineyards and surrounding areas, as well as the wine cultivars susceptibility, can help winegrowers to carry out the management. The objective of this study was evaluate the D. suzukii population dynamics in the field, on the forest border present around the vineyard and in its interior and evaluate the susceptibility of the main wine cultivars for São Joaquim municipality to the attack of D. suzukii in laboratory. In the vineyard, D. suzukii was monitored from November 2018 to May 2021 with weekly inspections. Plastic pot traps with a red stripe baited with the Droskidrink attractant were used, distributed among the vines and around the vineyard. Monitoring data were correlated with regional climate variables. In laboratory, through non-choice and free-choice test, the susceptibility to D. suzukii damage was evaluated in Chardonnay, Sauvignon Blanc, Sangiovese, Cabernet Franc, Cabernet Sauvignon and Merlot berries. Intact and artificially injured berries were offered to adults in plastic screened cages for 24h. Afterwards, the number of punctures, eggs, emerged adults and the period of egg-adult development were evaluated. The data were analyzed in the R environment. Through monitoring, it was found that the presence of D. suzukii adults was higher in the forest border (762) in the surroundings compared to inside of the vineyard (128). The precipitation reduced the population of D. suzukii inside the vineyard, while the average and maximum temperatures promoted an increase in the population. In free choice tests, the cultivar Sangiovese was susceptible to the attack and development of D. suzukii. The cultivar Cabernet Sauvignon showed reduced egg-adult development time compared to the other tested cultivars in no-choice test.

Error driven synapse augmented neurogenesis.

Capturing the learning capabilities of the brain has the potential to revolutionize artificial intelligence. Humans display an impressive ability to acquire knowledge on the fly and immediately store it in a usable format. Parametric models of learning, such as gradient descent, focus on capturing the statistical properties of a data set. Information is precipitated into a network through repeated updates of connection weights in the direction gradients dictate will lead to less error. This work presents the EDN (Error Driven Neurogenesis) algorithm which explores how neurogenesis coupled with non-linear synaptic activations enables a biologically plausible mechanism to immediately store data in a one-shot, online fashion and readily apply it to a task without the need for parameter updates. Regression (auto-mpg) test error was reduced more than 135 times faster and converged to an error around three times smaller compared to gradient descent using ADAM optimization. EDN also reached the same level of performance in wine cultivar classification 25 times faster than gradient descent and twice as fast when applied to MNIST and the inverted pendulum (reinforcement learning).

A high-density integrated map for grapevine based on three mapping populations genotyped by the Vitis18K SNP chip.

We present a high-density integrated map for grapevine, allowing refinement and improved understanding of the grapevine genome, while demonstrating the applicability of the Vitis18K SNP chip for linkage mapping. The improvement of grapevine through biotechnology requires identification of the molecular bases of target traits by studying marker-trait associations. The Vitis18K SNP chip provides a useful genotyping tool for genome-wide marker analysis. Most linkage maps are based on single mapping populations, but an integrated map can increase marker density and show order conservation. Here we present an integrated map based on three mapping populations. The parents consist of the well-known wine cultivars 'Cabernet Sauvignon', 'Corvina' and 'Rhine Riesling', the lesser-known wine variety 'Deckrot', and a table grape selection, G1-7720. Three high-density population maps with an average inter-locus gap ranging from 0.74 to 0.99cM were developed. These maps show high correlations (0.9965-0.9971) with the reference assembly, containing only 93 markers with large order discrepancies compared to expected physical positions, of which a third isconsistent across multiple populations. Moreover, the genetic data aid the further refinement of the grapevine genome assembly, by anchoring 104 yet unanchored scaffolds. From these population maps, an integrated map was constructed which includes 6697 molecular markers and reduces the inter-locus gap distance to 0.60cM, resulting in the densest integrated map for grapevine thus far. A small number of discrepancies, mainly of short distance, involve 88 markers that remain conflictual across maps. The integrated map shows similar collinearity to the reference assembly (0.9974) as the single maps. This high-density map increases our understanding of the grapevine genome and provides a useful tool for its further characterization and the dissection of complex traits.

The Effect of Harvest Date on Temporal Cannabinoid and Biomass Production in the Floral Hemp (Cannabis sativa L.) Cultivars BaOx and Cherry Wine

The objectives of this study were to model the temporal accumulation of cannabidiol (CBD) and tetrahydrocannabinol (THC) in field-grown floral hemp in North Carolina and establish harvest timing recommendations to minimize non-compliant crop production. Field trials were conducted in 2020 and 2021 with BaOx and Cherry Wine cultivars. Harvest events started two weeks after floral initiation and occurred every two weeks for 12 weeks. Per-plant threshed biomass accumulation exhibited a linear plateau trend. The best fit model for temporal accumulation of THC was a beta growth curve. As harvest date was delayed, total THC concentrations increased until concentrations reached their maximum, then decreased as plants approached senescence. Logistic regression was the best fit model for temporal accumulation of CBD. CBD concentrations increased with later harvest dates. Unlike THC concentrations, there was no decline in total CBD concentrations. To minimize risk, growers should test their crop as early as possible within the USDA’s 30-day compliance window. We observed ‘BaOx’ and ‘Cherry Wine’ exceeding the compliance threshold 50 and 41 days after flower initiation, respectively.

Development of two-level Design of Experiments for the optimization of a HS-SPME-GC-MS method to study Greek monovarietal PDO and PGI wines

Aroma is a key element in the description of wine's hedonistic character and commercial value. The volatile compounds that compose a wine's aroma belong to various very different chemical groups and their concentration varies from ppt to ppm. Therefore, the development of an analytical method able to cover such variability is a challenging task. In the present work, arduous method development was applied to reach optimal headspace solid-phase microextraction (HS-SPME) conditions, for the characterization of wine volatilome, by using a two-level screening-to-modelling Design of Experiments (DoE) approach. The optimized and comprehensive HS-SPME-GC-MS protocol was then used for the analysis of seventy wine samples of six monovarietal Greek Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI) white and red wine cultivars (Moschofilero, Assyrtiko, Savvatiano, Malagouzia, Agiorgitiko and Xinomavro). One hundred volatile metabolites were identified and semi-quantified in several concentration ranges according to variety. Fatty acids and their corresponding ethyl esters were found in higher concentrations in the white wines, while higher alcohols were characteristic for the red wines. Differences between the cultivars were evaluated through multivariate statistical analysis and PCA and OPLS-DA models. The results demonstrated that Moschofilero is a very aromatic and floral variety, as it is very rich in terpenic compounds, while Malagouzia and Agiorgitiko were characterized by isoamyl alcohol and ho-trienol, respectively.

Differences in defence-related gene expression and metabolite accumulation reveal insights into the resistance of Greek grape wine cultivars to <i> Botrytis </i> bunch rot

Berries of 13 Greek grape wine cultivars were evaluated for resistance to Botrytis bunch rot. Artificial inoculations on detached berries revealed that the Greek cultivars tested varied regarding their susceptibility to Botrytis cinerea. Cultivar (cv.) “Limnio” was found to be highly resistant, while higher susceptibility was observed on berries of cv. “Roditis”. To determine the molecular basis of the observed resistance or susceptibility of cv. “Limnio” and “Roditis”, an expression analysis of 12 defence-related genes, was carried out on artificially inoculated berries of the two cultivars at different time points after inoculation. Gene expression measurements in the resistant cv. “Limnio” showed that the artificial inoculation with the pathogen triggered the induction of genes encoding pathogenesis-related (PR) proteins such as chitinases (CHIT), polygalacturonase-inhibiting protein (PGIP), serine proteinase inhibitor (PIN) and enzymes involved in phytoalexin synthesis such as phenylalanine ammonia-lyase (PAL) and stilbene synthase (STS). In contrast, on the susceptible cv. “Roditis”, most of the same genes were down-regulated. Metabolomic analysis revealed significant differences in the initial metabolic profiles of “Limnio” and “Roditis” berries. Furthermore, in response to inoculation, the abundance of several metabolites increased in the resistant cultivar indicating intensification of metabolic processes. Proline and mannitol accumulation, as well as the modification of metabolites related to phenylpropanoid and lignin biosynthesis, are among the major players in defence responses of the “Limnio” cultivar. The above findings enhance our understanding of the resistance of Greek grape wine cultivars to B. cinerea and, at the same time, lay the foundation for breeding wine grape cultivars in the future.

Projections of Climate Change Impacts on Flowering-Veraison Water Deficits for Riesling and Müller-Thurgau in Germany

With global warming, grapevine is expected to be increasingly exposed to water deficits occurring at various development stages. In this study, we aimed to investigate the potential impacts of projected climate change on water deficits from the flowering to veraison period for two main white wine cultivars (Riesling and Müller-Thurgau) in Germany. A process-based soil-crop model adapted for grapevine was utilized to simulate the flowering-veraison crop water stress indicator (CWSI) of these two varieties between 1976–2005 (baseline) and 2041–2070 (future period) based on a suite of bias-adjusted regional climate model (RCM) simulations under RCP4.5 and RCP8.5. Our evaluation indicates that the model can capture the early-ripening (Müller-Thurgau) and late-ripening (Riesling) traits, with a mean bias of prediction of ≤2 days and a well-reproduced inter-annual variability for more than 60 years. Under climate projections, the flowering stage is advanced by 10–20 days (higher in RCP8.5) between the two varieties, whereas a slightly stronger advancement is found for Müller-Thurgau than for Riesling for the veraison stage. As a result, the flowering-veraison phenophase is mostly shortened for Müller-Thurgau, whereas it is extended by up to two weeks for Riesling in cool and high-elevation areas. The length of phenophase plays an important role in projected changes of flowering-veraison mean temperature and precipitation. The late-ripening trait of Riesling makes it more exposed to increased summer temperature (mainly in August), resulting in a higher mean temperature increase for Riesling (1.5–2.5 °C) than for Müller-Thurgau (1–2 °C). As a result, an overall increased CWSI by up to 15% (ensemble median) is obtained for both varieties, whereas the upper (95th) percentile of simulations shows a strong signal of increased water deficit by up to 30%, mostly in the current winegrowing regions. Intensified water deficit stress can represent a major threat for high-quality white wine production, as only mild water deficits are acceptable. Nevertheless, considerable variabilities of CWSI were discovered among RCMs, highlighting the importance of efforts towards reducing uncertainties in climate change impact assessment.

Development of new wine‐, dried‐ and tablegrape scions and rootstocks for Australian viticulture: past, present and future

This review highlights the contributions of CSIRO to the development of new scions and rootstocks for the Australian winegrape, driedgrape and tablegrape industries. Initially, CSIRO played a pivotal role in the selection of high-yielding Sultana clones which contributed over half the total Australian grape crop in the 1970s used for wine- and driedgrape production. It was also responsible for importation and evaluation of the Salt Creek (syn. Ramsey) rootstock which provided tolerance to root-knot nematodes and salinity and became the most widely adopted rootstock for the emerging Australian wine industry in the 1980–1990s. The CSIRO has also successfully bred or released several new grape cultivars. While the adoption rate for the CSIRO wine cultivars has been limited, CSIRO-selected cultivars dominate the Australian driedgrape industry, while CSIRO-released cultivars continue to play an important role in the Australian tablegrape industry. In the 1990s, CSIRO commenced the application of molecular biology techniques for grapevine germplasm improvement. Researchers from CSIRO were some of the first in the world to successfully regenerate transgenic grapevines and demonstrate the potential of this technology to produce low-browning driedgrapes and mildew-resistant premium winegrapes. More recently, the focus has shifted to the mapping of resistance loci from wild grape species and their introgression into new winegrape scions to provide resistance to mildews and new rootstocks to provide durable resistance to rootknot nematodes and phylloxera. Finally, this review considers some future challenges faced by the Australian grape industries and how these might be addressed using conventional or molecular breeding strategies.

Assessment of phenology, growth characteristics and berry composition in a hot Australian climate to identify wine cultivars adapted to climate change

Background and Aims The phenology, growth traits and fruit composition of cultivars in the CSIRO germplasm collection, located in a hot Australian region, were assessed to identify those adapted to climate change. Methods and Results The study involved 465 cultivars assessed over four seasons. Differences in key traits included a 5-week range in budburst; a 4-month harvest window; a twofold difference in the growth period from budburst to harvest; a fivefold difference in fruitfulness and in leaf area index; a 15-fold difference in berry mass; and a five- to 15-fold difference in berry mineral ion concentration and large differences in fruit composition. The latter included pH (range 3.48–4.95), titratable acidity (1.60–9.07 g/L), tartaric acid (2.20–7.95 g/L), malic acid (0.80–7.74 g/L), yeast assimilable nitrogen (70–505 mg/L) and, in red wine cultivars, total anthocyanins (0.04–5.79 mg/g) and phenolic compounds (0.55–3.60 a.u.). Conclusions Cultivars grown under hot conditions with late budburst to minimise frost risks; short growth periods and small canopies to improve water use efficiency; and early and late ripening to extend the season have been identified. Early ripening cultivars had better fruit composition than late ripening cultivars. Significance Opportunities to broaden genetic diversity will enhance the capability of the wine industry to meet challenges associated with climate change. Poor fruit composition, however, associated with high pH is a limiting factor under hot conditions.

Rootstock effects on growth and fruit composition of low‐yielding winegrape cultivars grown in a hot Australian climate

Background and Aims The use of rootstocks to enhance the performance of low-yielding wine cultivars grown under hot irrigated conditions was studied. Methods and Results Field performance and grape composition of low-vigour cultivars (Chasselas, Egiodola, Ehrenfelser, Gamay, Perdea, Reichensteiner and Roussanne) grown as own roots or grafted on rootstocks (1103 Paulsen, Dog Ridge, Ramsey, Schwarzmann and SO4) were assessed over three seasons. Across all cultivars, yield of own roots, SO4 and Schwarzmann was similar. Ramsey and 1103 Paulsen produced a higher yield without a major effect on juice composition. Dog Ridge produced excessive vigour and poor grape composition. Across the scion–rootstock combinations, high vine vigour, yield and berry mass were associated with high juice pH, K+ and malic acid and low tartaric acid. Rootstock effects on juice K+, tartaric and malic acid were stable and independent of the scion cultivar. Conclusions The performance of low-vigour cultivars was enhanced by grafting on 1103 Paulsen and Ramsey. ‘Scion conferred root vigour’ was found under field conditions. Significance of the Study The genetic diversity of cultivars available for wine production can be broadened by adoption of rootstocks for low-vigour cultivars. Rootstock selection requires knowledge of inherent scion vigour and conferred rootstock vigour.

Direct quantification of red wine phenolics using fluorescence spectroscopy with chemometrics

Phenolic compounds are secondary metabolites known to play crucial roles in important chemical reactions impacting the mouthfeel, colour and ageing potential of red wine. Their complexity has resulted in a number of advanced analytical methods, which often prevent routine phenolic analysis in winemaking. Fluorescence spectroscopy could be an alternative to current spectrophotometric techniques and its combination with chemometrics was investigated for its suitability in directly quantifying phenolic content of unaltered red wine and fermenting samples. Front-face fluorescence was optimised and used to build predictive models for total phenols, total condensed tannins, total anthocyanins, colour density and polymeric pigments. Machine learning algorithms were used for model development. The most successful models were built for total phenols, total condensed tannins and total anthocyanins with coefficient of determination (R2cal) and RMSECV of 0.81, 0.89, 0.80 and 5.71, 104.03 mg/L, 60.67 mg/L, respectively. The validation results showed R2val values of 0.77, 0.8 and 0.77, and RMSEP values of 7.6, 172.37 mg/L and 76.57 mg/L, respectively. A novel approach for the classification of South African red wine cultivars based on unique fluorescent fingerprints was also successful with an overall cross validation score of 0.8. The best classification ability (validation score = 0.93) was shown for the data set containing only fermenting wines for the most widely represented cultivars (>20 samples). This approach may provide a useful tool for authentication and quality control by regulatory bodies.

Varietal Response to Sour Bunch Rot in Polish Grapevine Genetic Resources

The aim of this study was to assess the resistance to sour rot of twenty-eight valuable cultivars of grapevine for wine production and twenty-five cultivars of table grapevine with diverse geographic and genetic origins, and to explain the causes of varied resistance based on the features related to the morphology, biology and ecology of assessed genotypes. The study was conducted for six years in the grapevine field collection of the National Institute of Horticultural Research in Skierniewice (Poland, latitude 51.9627 N, longitude 20.1666 E). Sour rot was severe in three seasons with abundant rainfall during the berry ripening stage. The number of wine and table cultivars in particular classes of resistance (mean value for three years) was as follows: very little or little—9 (wine) and 9 (table), medium—9 (wine) and 3 (table), high or very high—10 (wine) and 13 (table). The severity of bunch sour rot was positively correlated with single berry weight (moderate or weak correlation), bunch density and single bunch weight (very weak or weak correlation), and negatively correlated with thickness of berry skin (strong correlation) and the time of the beginning of veraison (weak correlation). Cultivars that were characterized by such agrobiological and ecological features as easy detachment of the berry from the pedicel, sensitivity to berry skin cracking, frequent damage to the skin by insects, and sensitivity to sunburn, were more heavily exposed to sour rot.

Is aromatic terpenoid composition of grapes in Northwestern Iberian wine cultivars related to variation in VviDXS1 gene?

BACKGROUND: Monoterpenes and C13-norisoprenoids are key terpenoid compounds for wine aroma. The enzyme encoded by VviDXS1 participates in terpenoid biosynthesis in grapevine fruits and gain-of-function mutations in this gene lead to characteristic muscat aroma. OBJECTIVE: To assess for VviDXS1 contribution to aroma variation in Northwestern Iberian wine cultivars, we resequenced this gene in 111 cultivars and compared grape juice terpenic composition in 12 of them. METHODS: VviDXS1 was capture-targeted for resequencing with Illumina paired-end reads, SAMtools was used for variant calling and gene haplotypes were reconstructed with PHASE. Monoterpenes and C13-norisoprenoids were quantified in free and glycosidically-bound forms from grape juice by gas chromatography-mass spectrometry. RESULTS: Terpenic composition discriminated between muscat, terpenic and neutral profiles across cultivars. While the terpenic profile of Loureira and Albariño white cultivars was not associated with muscat-like mutations, Albariño carries a V34L substitution in VviDXS1 that is also present in other aromatic cultivars and was not reported before. Tempranillo and Cabernet Sauvignon red cultivars accumulated higher levels of C13-norisoprenoids, which was not associated with specific variation in VviDXS1. CONCLUSIONS: Apart from the uncharacterized substitution present in Albariño, findings suggest that terpenoid pathway-related genes other than VviDXS1 could contribute to the aromatic attributes of these cultivars.

THE INFLUENCE OF CLIMATIC CONDITIONS ON OENOLOGICAL PARAMETERS OF SOME WINE CULTIVARS FROM DIFFERENT ROMANIANVINEYEARD

A study concerning the influence of climatic conditions on the oenological parameters of wine cultivars was carried out using six wine cultivars under the climatic conditions of 2019. Wine samples were taken from Ştefăneşti–Argeş, Babadag and Drăgăşani viticultural centres. Determination of the oenological parameters has been made for the following wine cultivars: Riesling Italian, Fetească Regală, Sauvignon Blanc, Feteascǎ Neagră, Merlot and Pinot Noir. The chemical parameters were determined using a Mindray BS 200 oenological analyser and the statistical analysis of the results was carried out using the Duncan test. A correlation was made between the parameters of the six wine cultivars from the three viticultural centres, focusing on the correlations between the total polyphenols of wines and their antioxidant activity.