Terroir 2004 banner
IVES 9 IVES Conference Series 9 Sugar loading and phenolic accumulation as affected by ripeness level of Syrah/R99 grapes

Sugar loading and phenolic accumulation as affected by ripeness level of Syrah/R99 grapes

Abstract

[English version below]

Le chargement et l’accumulation des sucres ainsi que la biosynthèse des phénols ont été étudiés sur la Syrah, dans le cadre d’un programme de recherche de paramètres qui permettraient de déterminer une ou plusieurs qualités de raisin en relation avec des styles de vins pour un terroir donné. La relation entre la dynamique d’accumulation des sucres et, en parallèle, la biosynthèse des phénols a été étudiée sur Syrah/99R plantée dans un vignoble situé sur la station expérimentale de ARC Infruitec-Nietvoorbij, Stellenbosch (Afrique du Sud). La cinétique des analyses a été réalisée depuis le stade post floraison (nouaison) jusqu’au stade sur-maturation. Les vignes sont conduites en Espalier (2,75m x 1,5m), les rangs sont orientés nord – sud, le vignoble est en pente orientée est. Une irrigation par micro aspersion est appliquée de la nouaison à la véraison. La hauteur de végétation est de 1,4 m, avec 3 hauteurs de fils de palissage. Les vignes sont ébourgeonnées, palissées et écimées. La dynamique d’accumulation des sucres par baie a été étudiée à l’aide d’un protocole développé par Deloire et al., 2004 (sous presse). La biosynthèse des phénols (tanins totaux et leur degré de polymérisation, proanthocyanidols et anthocyanes) a été étudiée par spectrophotométrie et HPLC pour les anthocyanes. Le sucre est utilisé comme indicateur des relations vigne – baie (relations source – puits).
Les tanins totaux (TT) de la baie sont synthétisés depuis l’anthèse jusqu’à la véraison. Leur concentration augmente durant la croissance herbacée des baies. Elle diminue en concentration de véraison à maturation, alors que durant cette période, la quantité de TT par baie est stable. Quand les sucres sont utilisés comme indicateur physiologique, il ressort clairement que la biosynthèse des anthocyanes évolue, par baie, jusqu’à ce que ces dernières atteignent un contenu en sucre de 20 – 21 °Brix. Après ce point, l’évolution des anthocyanes par baie est indépendante de l’évolution du contenu en sucre par baie, qui se fait alors essentiellement par concentration (perte d’eau de la baie). Le chargement actif des baies en sucre est dépendant de la photosynthèse des feuilles et la régulation du déchargement phloémien du sucre dans les baies semble en partie dépendante du microclimat des grappes et des baies elles mêmes. Le chargement actif en sucre de la baie n’est pas directement corrélé à son volume.

Sugar loading and phenolic accumulation in Syrah grapes were investigated as part of an elaborate study to determine parameters that would indicate high grape quality and different grape and wine styles on a particular terroir. The relationship between the dynamics of sugar loading and phenolic accumulation in the berries of a Syrah/R99 vineyard, situated at the ARC Infruitec-Nietvoorbij , in the Stellenbosch region (South Africa), was investigated from pea size stage (green berry) to late maturity. Vines were vertically trained and spaced 2.75 x 1.5 m in north-south orientated rows on a terroir with Glenrosa soil and a west-facing slope. Microsprinkler-irrigation was applied at pea berry size and at véraison stages. The 1.4 m high canopies were suckered, shoot-positioned and topped and accommodated by means of three sets of double wires. The dynamics of berry sugar loading were studied by a method from Deloire et al, 2004 (under publication), the berry phenolic composition (total tannins and polymerisation, proanthocyanidins, anthocyanins) was analysed by spectrophotometry and anthocyanins by HPLC. Sugar was used as physiological indicator of the plant-berry (source-sink) relationship and as bunch microclimatic indicator.
The total tannin (TT) component in the berry was synthesised from anthesis to véraison. The TT concentration increased during the green berry growth stages and decreased during ripening as the berry increased in volume. The TT per berry also increased during the green berry growth stages, but kept stable during ripening. When sugar content per berry is used as physiological indicator, it is clear that anthocyanin biosynthesis occurred until a specific berry sugar content, i.e. 20 – 21 0Brix, is reached. After this point, anthocyanin evolution per berry seemed independent of berry sugar evolution, which is at that time mainly due to concentration (berry water loss) than to loading. Thus, although berry sugar loading is dependent on photosynthetic activity of the leaves, the regulation of sugar phloem unloading in the berry sink seemed to be, in part, affected by the microclimate that the berry experienced. Berry sugar loading was not directly correlated with berry volume.

DOI:

Publication date: January 10, 2022

Issue: Terroir 2004

Type: Article

Authors

A. Deloire (1), E. Kraeva (1), M. Martin (2) et J.J. Hunter (3)

(1) Agro Montpellier, UMR 1083 « sciences pour l’œnologie et la viticulture », 2 place Viala, 34060 Montpellier cedex 1, France
(2) INRA, Unité expérimentale de Pech Rouge, 11430 Gruissan, France
(3) ARC Infruitec-Nietvoorbij, Private Bag X5026, 7599 Stellenbosch, South Africa

Contact the author

Keywords

Vitis vinifera, bunch, sugar, microclimate, indicator, vine functioning

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

austrianvineyards.com: online viewer of all designations of Austrian wine

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.

Protected Designation of Origin (D.P.O.) Valdepeñas: classification and map of soils

The objective of the work described here is the elaboration of a map of the different types of vineyard soils that to guide the famers in the choice of the most productive vine rootstocks and varieties. 90 vineyard soils profiles were analysed in the entire territory of the Origen Denominations of Valdepeñas. The sampling was carried out in 2018 (June to October) by making a sampling grid, followed by photointerpretation and control in the field. The studied soils can be grouped into 9 different soil types (according to FAO 2006 classification): Leptosols, Regosols, Fluvisols, Gleysols, Cambisols, Calcisols, Luvisols and Anthrosols. A map showing the soil distribution with different type of soils has been made with the ArcGIS program. Regarding to the choice of rootstock, Calcisoles are soils with a high active limestone content, so the rootstocks used in these soils must be resistant to this parameter; Luvisols are deep soils with high clay content, so they will support vigorous rootstocks. Because the cartographic units are composed of two or more subgroups, with are associated in variable proportions, 9 different soil associations have been established; Unit 1: Leptosols, Cambisols and Luvisols (80%, 15% and 5% respectively); Unit 2: Cambisols with Regosols and Luvisols (40%, 30% and 30% respectively); Unit 3: Cambisols and Gleysols with Regosols (40%, 40% and 20% respectively); Unit 4: Regosols with Cambisols, Leptosols and Calcisols (40%, 30%, 15% and 15% respectively); Unit 5: Cambisols, Leptosols, Calcisols and Regosols (25% each of them); Unit 6: Luvisols with Cambisol and Calcisols (80%, 10% and 10% respectively); Unit 7: Luvisols and Calcisols with Cambisols (40%, 40% and 20% respectively); Unit 8: Calcisols with, Cambisols and Luvisols (80%, 10% and 10% respectively); Unit 9: Anthrosols. These study allow to elaborate the first map of vineyard soils of this Protected Designation of Origin in Castilla-La Mancha.

Understanding graft union formation by using metabolomic and transcriptomic approaches during the first days after grafting in grapevine

Since the arrival of Phyloxera (Daktulosphaira vitifolia) in Europe at the end of the 19th century, grafting has become essential to cultivate Vitis vinifera. Today, grafting provides not only resistance to this aphid, but it used to adapt the cultivars according to the type of soil, environment, or grape production requirements by using a panel of rootstocks. As part of vineyard decline, it is often mentioned the importance of producing quality grafted grapevine to improve vineyard longevity, but, to our knowledge, no study has been able to demonstrate that grafting has a role in this context. However, some scion/rootstock combinations are considered as incompatible due to poor graft union formation and subsequently high plant mortality soon after grafting. In a context of climate change where the creation of new cultivars and rootstocks is at the centre of research, the ability of new cultivars to be grafted is therefore essential. The early identification of graft incompatibility could allow the selection of non-viable plants before planting and would have a beneficial impact on research and development in the nursery sector. For this reason, our studies have focused on the identification of metabolic and transcriptomic markers of poor grafting success during the first days/week after grafting; we have identified some correlations between some specialized metabolites, especially stilbenes, and grafting success, as well as an accumulation of some amino acids in the incompatible combination. The study of the metabolome and the transcriptome allowed us to understand and characterise the processes involved during graft union formation.

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

Impact of long term agroecological and conventional practices on subsurface soil microbiota in Macabeu and Xarel·lo vineyards

There is a growing trend on the transition from conventional to agroecological management of vineyards. However, the impact of practices, such as reduced-tillage, organic fertilization and cover crops, is not well-understood regarding the soil microbial diversity, and its relationship with the soil physicochemical properties in the subsurface depth near the rooting zone. Soil bacterial diversity is an important contributor towards plant health, productivity and response to environmental stresses. A field experiment was conducted by sampling subsurface soil bacterial community (NGS and qPCR) near to the root zone of Macabeu and Xarel·lo vineyards, located at the Penedes. 3 organic (ECO) and 3 conventional (CON) vineyards, with more than 10 years of respective management were sampled (n=5 each plot). ECO practices did not affect bacterial and fungal abundance but increased significantly the ammonium oxidizing bacteria and alpha-diversity (Inv.Simpson). Interestingly beta-diversity was significantly affected by the management strategy. ANOSIM-tests revealed a significative effect of the management (ecological vs conventional) and plot, on the soil microbial structure (ASV abundance). Main phyla depicted were Proteobacteria, Actinobacteria and Acidobacteria, whose relative abundances were not affected by the management. EdgeR assay revealed a significant increase of Cyanobacteria and decrease of Gemmatimonadetes and Firmicutes phyla in ECO. Interestingly, the grapevine variety was not correlated with the soil microbial community structure. Mantel-test revealed an important correlation (Spearman) of some physicochemical parameters with the soil microbiota structure, in order of importance: texture, EC, pH Ca/Mg, Mg/P, K+, Mg2+, Ca2+, SO42-, and OM. N-NH4 and NTK, which were higher in the ECO managed soils, did not correlated significantly with the soil microbiome population. The results revealed the importance of combining a deep physicochemical characterization of each replicate with the microbial diversity assessment to gain better insights on the relationship between soil microbiome and vineyard management.