European collaboration for the grapevine phenotypic diversity exploitation

Trabajo presentado en la Final Conference Progress in Vitis Vinifera diversity evaluation and use, celebrada en Lisboa del 7 al 9 de octubre de 2014.-- Rustioni, Laura et al.Cost action FA1003 - GRAPENET. East-West Collaboration for Grapevine Diversity Exploration and Mobilization of Adaptive Traits for Breeding.Common limits for phenotyping are costs in terms of equipment, specialized researchers, and time. Moreover, phenotyping requires specific methods in relation to the studied traits, and each method is generally designed to highlight very specific characteristics of the singular trait. Thus, the obtained results are not easily comparable between different institutions. However the data sharing is clearly the most powerful approach to limit the costs and efforts optimizing the obtained results in term of number of studied accessions. It should be stressed that funds are another great limit in research, especially in East countries, where the most interesting cultivar variability is preserved.Peer Reviewe

First results of the European grapevine collections' collaborative network: Validation of a standard eno-carpological phenotyping method

Rustioni, L. et al.A standard protocol for phenotyping structural and compositional aspects of the grape berry has been adopted by 18 East and West European germplasm collections during one season by testing a total of 469 accessions, including reference cultivars as well as local and minor germplasm accessions of specific interest. The protocol consists in the collection of triplicates for 26 phenotypic traits, from biological samples, each formed by 10 berries collected from 9 representative bunches from every analyzed accessions. The protocol concatenates the data from measurements and acquisitions, with the objective to generate new derived variables, which are expressed with different units (%; content per kg of grapes, per berry, per g of tissue). For each variable, the Least Significant Differences (LSD), to contrast a pair of single accession mean values, and the Confidence Intervals (CI), to estimate each single accession mean value, were computed. The application of the protocol revealed satisfactory results with high accuracy and efficiency in estimation of phenotypic traits of each accession. The whole data set will be useful for researchers, breeders and viticulturists in yield evaluation of grapevine cultivars, as well as in comparative analyses of environment-variety interaction.Joint publication of the COST Action FA1003 “East-West Collaboration for Grapevine Diversity Exploration and Mobilization of Adaptive Traits for Breeding”.Peer Reviewe

Optical properties of berry epicuticular waxes in four Georgian grape cultivars (Vitis vinifera L.).

The epidermis of plant shoot organs is generally covered by epicuticular waxes. The role of this layer is related mainly to the protection of the inner tissues from biotic and abiotic stresses. In this study, attention is focused on the optical properties of the berry epicuticular waxes of the grapevine (Vitis vinifera L.) at fruit ripening. The reflectance of the berry surface was measured before and after chloroform treatments in four Georgian grape cultivars grown in northern Italy. Epicarp optical properties were underlined at different wavelengths (341 to 1025 nm) for each cultivar. The results show that the berry waxes have several optical properties; it is possible that their main eco-physiological effect is to provide specific protection against different types of radiation. Besides the physiological aspects, the results are interesting also from a technical point of view in the field of interpretation of reflectance measurements carried out by non-invasive instruments

Neglected cultivars for the Mtskheta-Mtianeti region (East Georgia): ampelography, phenology, and agro-climatology

Georgia is an important source of grapevine intra-specific variability for viticulture. This biodiversity can be a suitable tool to face the challenge of climate change. Nevertheless, it is important to take into account the interaction between the interest genotype and the local environment, whose climate is changing due to global heating. In this work, we put in relation the phenotypic behavior of some neglected Georgian cultivars (‘Tabidziseuli’, ‘Daisi’, ‘Qvelouri’, ‘Bazaleturi Colikouri’) from the Mtskheta-Mtianeti Georgian region to the agro-climatology of the region itself. The phenological phases and the vegetation length of these four grape varieties were described, as well as their principal ampelographic characters. The impact of global heating on the agro-climatology of the Mtskheta-Mtianeti region has also been established, by comparing the sum of active temperatures (>10°C) of multi-years (1948-2017) with those calculated for the future scenario (2020-2050, temperature increase by 2°C). Based on this comparison, three agro-climatic zones have been confirmed within the region: dry subtropical, mountain and high mountain. The scenario of temperature increase by 2°C in the next three decades will cause the sum of active temperatures to reach 3900-4000°C in the dry subtropical zone, 3400-3500°C in the mountain zone and 1900-2000°C in the high mountain zone. Considering the vegetation length of the cultivars analyzed, it can be expected a shift of the most suitable sites for viticulture from the dry subtropical zone to the mountain area. High mountain seems not to be suitable for the cultivation of the studied cultivars. Given this environmental variability within the region, the increase in temperature will not suppress viticulture in Mtskheta-Mtianeti, if the real temperature does not exceed the level predicted by scenario

Comparison between the Grape Technological Characteristics of Vitis vinifera Subsp. sylvestris and Subsp. sativa

none7siWine has been produced in Georgia since the 6th millennium BC. The processes of cultivar selection and breeding started with wild grapes Vitis vinifera L. ssp. sylvestris Gmel. and included multiple introgression events—from the wild to domestication. This article aims at improving the knowledge concerning the history of winemaking through a comparison of the Vitis vinifera subsp. sylvestris and subsp. sativa. Grapes of Vitis vinifera subsp. sylvestris were grown in an ampelographic collection and vintages 2017–2020 were analyzed. The obtained data were compared to a wider dataset available in literature concerning Vitis vinifera subsp. sativa, demonstrating the central role of grape morphology in the domestication process. This evidence suggests that the technological value of the cultivars played an important role in the selection process. In vintages 2017, 2018, and 2019, wines were produced with Vitis vinifera subsp. sylvestris grapes and compared with Cabernet Sauvignon and Saperavi vinifications. For all the vintages, the fermentations took shorter time for wild grape, despite the highest content of total phenols. Learning from the past, Vitis vinifera subsp. sylvestris might still be an interesting genetic resource for future breeding programs. Furthermore, the possible combination of wild and domesticated grapes can make possible the production of wines with long ageing, exalting their own characteristics.openMaghradze, David; Kikilashvili, Shengeli; Gotsiridze, Olan; Maghradze, Tamar; Fracassetti, Daniela; Failla, Osvaldo; Rustioni, LauraMaghradze, David; Kikilashvili, Shengeli; Gotsiridze, Olan; Maghradze, Tamar; Fracassetti, Daniela; Failla, Osvaldo; Rustioni, Laur

Microclimate of Grape Bunch and Sunburn of White Grape Berries: Effect on Wine Quality.

This research aimed to evaluate the composition of wines made with white grapes which are particularly susceptible to sunburn symptoms due to the absence of anthocyanin. Sunburn is a complex physiological dysfunction leading to browning or necrosis of berry tissues. In vintage 2021, the canopy of ‘Verdeca’ grapevines grown in Salento, South Italy, was differently managed by sun exposing or shading the bunches. Micrometeorological conditions were studied at different levels. Grapes were vinified, comparing the winemaking with and without skin maceration. The vegetative-productive balance of plants was not substantially modified. On the contrary, a significant effect was observed on the quality and quantity of grapes produced: smaller berries with sunburn symptoms were found on unshaded bunches. This influenced the percentage distribution among skin, pulp and seeds, causing a decrease in must yield of up to 30%. The pH was significantly higher in macerated wines made using shaded grapes, due to a lower titratable acidity and to significant impacts on the acid profile. Obviously, maceration produced a higher extraction of phenolics in wines, which reached their maximum in wines made with sunburned grapes. The absorbance at 420 nm, index of yellow color, was also significantly higher in sunburned grapes, indicating greater oxidation. Even though excessive grape sun-exposure could negatively affect the perception of white wines made without maceration (resulting in more oxidative character), the sensory quality of orange/amber wines was not significantly impacted by the presence of sunburned grapes. Thus, this winemaking technique could be particularly interesting to set up a production strategy adapted to viticultural regions strongly affected by climate change

A New Strategy to Improve Vineyard Resilience: Grapevine Morphological Adaptation to Short-Term Nitrogen Deficiency

Nitrogen (N) deficiency causes a morphological disequilibrium between shoots and roots, favoring hypogeal growth. Our hypothesis is that short-term nitrogen deficiency could induce an increase in vine resilience, inducing root growth before the appearance of significant dysfunctions in the epigeal part of the plant. Then, nitrogen availability could be promptly restored through a well-thought-out fertilization plan. In this experiment, two table grape cultivars grafted onto three different rootstocks were studied in three hydroponic growing conditions characterized by different nitrogen availability. After 53 days of treatment, plant morphologies were described, and leaf photosynthetic pigments were quantified. The short-term nitrogen deficiency induced root growth, leading to significantly different proportions among the hypogeal and the epigeal parts, despite no significant differences were recorded concerning shoot growth. Some small differences in the leaf pigmentations indicated an incipient symptom of nitrogen deficiency, and significant differences in the phytomer morphology indicated the possibility of developing low-cost indices for prompt identification of incipient symptoms. This will allow the exploitation of the advantages of short-term nitrogen deficiency while avoiding negative effects on shoot growth by promptly restoring the nitrogen availability

Influence of freezing and heating conditions on grape seed flavan-3-ol extractability, oxidation, and galloylation pattern

In cool-climate viticulture, the short growing season can influence grape seed maturation by reducing the apparent oxidation of flavan-3-ol monomers and associated increase in seed browning. A reduction in seed maturation increases the potential extraction of flavan-3-ol monomers into wine during maceration operations, heightening bitterness. Here, we carried out a 2 × 2 factorial experiment to test the ability of freezing and heating treatments to advance maturation (decrease flavan-3-ol, improve browning) of (Vitis vinifera L.) Pinot noir and Cabernet Sauvignon seeds over a 24-h incubation period. Only freezing significantly increased seed browning in both cultivars. Subsequent correlations with seed flavan-3-ol monomer concentrations suggest that freezing enhanced the oxidation of these compounds. Interestingly, natural ripening and freezing reduced galloylated flavan-3-ol monomers to a greater extent than non-galloylated ones. This study provides new information regarding the susceptibility of flavan-3-ol monomers to freezing and heating, and also suggests that freezing can advance the maturation the seeds of under-ripe red vinifera grapes

Metabolomic NMR analysis and organoleptic perceptions of pomegranate wines: Influence of cultivar and yeast on the product characteristics

: Pomegranate (Punica granatum L.) fruits are a historical agricultural product of the Mediterranean basin that became increasingly popular in the latest years for being rich in antioxidants and other micronutrients, and are extensively commercialized as fruits, juice, jams and, in some Eastern countries, as a fermented alcoholic beverage. In this work, four different pomegranate wines specifically designed using combinations of two cultivars (Jolly Red and Smith) and two yeast starters with markedly different characteristics (Saccharomyces cerevisiae Clos and Saccharomyces cerevisiae ex-bayanus EC1118) were analyzed. The chemical characterization of the wines together with the originating unfermented juices was performed by 1H NMR spectroscopy metabolomic analysis. The full spectra were used for unsupervised and supervised statistical multivariate analysis (MVA), namely Principal Component Analysis (PCA), Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), and sparse PCA (SPCA). The MVA of the wines showed a clear discrimination between the cultivars, and a smaller, yet significant, discrimination between the yeasts used. In particular, a higher content of citrate and gallate was observed for the Smith cv. and, on the contrary, a statistically significant higher content of fructose, malate, glycerol, 2,3 butanediol, trigonelline, aromatic amino acids and 4-hydrophenylacetate was observed in Jolly Red pomegranate wines samples. Significant interaction among the pomegranate cultivar and the fermenting yeast was also observed. Sensorial analysis was performed by a panel of testing experts. MVA of tasting data showed that the cultivar significantly affected the organoleptic parameters considered, while the yeast had a minor impact. Correlation analysis between NMR-detected metabolites and organoleptic descriptors identified several potential sensorially-active molecules as those significantly impacting the characteristics of the pomegranate wines

Dynamics of the Fermentation Process and Chemical Profiling of Pomegranate (Punica granatum L.) Wines Obtained by Different Cultivar×Yeast Combinations

Pomegranate (Punica granatum L.) is one of the historical tree crops in the Mediterranean region and is nowadays commercialized for its beneficial properties in the form of fruits, juice, jams and, in some East countries, as fermented juice (pomegranate wine). However, pomegranate wines are not established as a common beverage in Western countries. In this work, we produced pomegranate wines using two cultivars and two yeasts (Saccharomyces cerevisiae strain Clos and S. cerevisiae ex-bayanus strain EC1118) with contrasting characteristics. A comprehensive chemical profile of the wines was obtained. Notable differences were observed in the function of the cultivars and the yeasts. Different cultivar×yeast combinations provided wines with clearly different chemical profiles and specific features in the patterns of organic acids, phenolics, and volatile compounds. This highlights the opportunity to obtain tailored pomegranate wines with desired chemical profiles and, consequently, sensory properties, through management optimization of pomegranate winemaking. In this view, pomegranate wines have the potential to become an established beverage in Western countries