terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Impact of temperature and solar radiation on grape composition variability in the Saint-Emilion winegrowing area 

Impact of temperature and solar radiation on grape composition variability in the Saint-Emilion winegrowing area 

Abstract

Grape composition is strongly influenced by climate conditions. Their expected modifications in near future, notably because of increased temperatures, could significantly modify the biochemical composition of berries at harvest, and thus wine typicity and quality. Elevated temperatures favor sugar accumulation in grapes, enhance malic acid degradation and modify the amino acid content. They also reduce significantly anthocyanin accumulation in Merlot,leading to the imbalance between anthocyanins and sugars, while no significant effects on final anthocyanin levels were reported in Tempranillo[1] and finally affect aromas or aroma precursors. However, at local scale, several other environmental factors also contribute to the overall berry composition variability between nearby vineyards and the impact of each individual factor is difficult to identify. In this context, the objective of our study was to clarify the effect of temperature variability across a network of vineyards from the Saint-Emilion and Pomerol wine producing areas, by selecting well-characterized Merlot plots presenting significant temperature differences and gradients at various time scales linked to environmental factors[2].

The selected sites were characterized by similar soils, vine age and training system. The average temperature difference during the ripening period was about 2°C between the coldest and warmest sites. Samples of 20 to 50 berries were collected at different phenological stages from véraison to maturity in 2019 and 2020. In order to further investigate the putative impact of cluster exposure to solar radiation, the biochemical composition of berries in clusters from each side of differently oriented rows (E/W or N/S) was evaluated separately and combined with RNA-seq technology to screen differentially expressed genes at the transcriptome level.

Results showed significant effects on grape composition and gene expression profiles in relation with temperature, site, and bunch azimuth, with a noteworthy impact of temperature and solar radiation exposure on anthocyanin content in grape skins.

Acknowledgements: this project was supported by “Conseil Interprofessionnel des Vins de Bordeaux “ (CIVB) n°51640/18008/9/10

References :

  1. Arrizabalaga-Arriazu, M. et al, (2020). High temperature and elevated CO2 modify berry composition of different clones of grapevine (Vitis vinifera L.) cv. Tempranillo, Front. Plant Sci. dec 2020, 11:603687. doi: 10.3389/fpls.2020.603687
  2. de Rességuier L et al (2020). Temperature variability at local scale in the Bordeaux area. Relations with environmental factors and impact on vine phenology. Front Plant Sci. may 20,11:515. doi: 10.3389/fpls.2020.00515

DOI:

Publication date: October 11, 2023

Issue: ICGWS 2023

Type: Poster

Authors

Ghislaine Hilbert-Masson1, Christel Renaud1, Philippe Pieri1, Laure de Rességuier1, Cécile Thibon2, Céline Cholet2, David Lecourieux1, Sabine Guillaumie1, Nathalie Ollat1

1 EGFV, Univ. Bordeaux, Bordeaux Sciences Agro, INRAE, ISVV, 33882 Villenave d’Ornon, France
2 Univ. Bordeaux, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, 33140 Villenave d’Ornon, France / Bordeaux Sciences Agro, 33170 Gradignan, France

Contact the author*

Keywords

vineyard, Merlot, climate change, solar radiation, metabolites, anthocyanins

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Atypical aging and hydric stress: insights on an exceptionally dry year

Atypical aging (ATA) is a white wine fault characterized by the appearance of notes of wet rag, acacia blossoms and naphthalene, along with the vanishing of varietal aromas. 2-aminoacetophenone (AAP) – a degradation compound of indole-3-acetic acid (IAA) – is regarded as the main sensorial and chemical marker responsible for this defect. About the origin of ATA, a stress reaction occurring in the vineyard has been looked as the leading cause of this defect. Agronomic, climatic and pedological factors are the main triggers and among them, drought stress seems to play a crucial role.[1]

Oenological compatibility of biocontrol yeasts applied to wine grapes 

Antagonistic yeasts applied to wine grapes must be compatible with the thereafter winemaking process, avoiding competition with the fermentative Saccharomyces cerevisiae or affecting wine flavour. Therefore, fifteen epiphytic yeasts (6 Metschnikowia sp., 6 Hanseniaspora uvarum, 3 Starmerella bacillaris) previously selected for its biocontrol ability against Alternaria on wine grapes were evaluate for possible competition with S. cerevisiae by the Niche Overlap Index (NOI) employing YNB agar media with 10 mM of 17 different carbonate sources present in wine grapes (proline, asparagine, alanine, glutamic acid, tirosine, arginine, lisine, methionine, glicine, malic acid, tartaric acid, fructose, melibiose, raffinose, rhamnose, sucrose, glucose).

Effect of ultraviolet B radiation on pathogenic molds of grapes

The fungicidal effect of UV-C radiation (100-280 nm wavelength) is well known, but its applicability for the control of pathogenic molds of grapes is conditioned by its effect on the host and by the risks inherent in its handling[1].
As an alternative, the effect in vitro of UV-B radiation (280-315 nm) on the main pathogenic molds of grapes has been studied: Botrytis cinerea, Aspergillus niger, Penicillium expansum and Rhizopus stolonifer.

Polyphenol content of cork granulates at different steps of the manufacturing process of microagglomerated stoppers treated with supercritical CO2 used for wine bottling

The wine closure industry is mainly divided into three categories: screw caps, synthetic closures, and cork-based closures. Among this latter, microagglomerated cork stoppers treated with supercritical CO2 are now widely used, especially to avoid cork taint contaminations[1]. They are designed with cork granules obtained from cork offcuts of the punching process during the natural cork stoppers production. A previous study[2] showed that these stoppers released fewer polyphenols in 12 % (v/v) hydroalcoholic solution than natural cork stoppers.

Characterization of non-cultivated wild grapevines in Extremadura (Spain) 

Several Eurasian wild grapevine populations were found along Extremadura region (southwestern Spain). For conservation and study, one individual from four different populations (named L1, L2, L5 and L6) was vegetatively propagated and planted at Instituto de Investigaciones Agrarias Finca La Orden (CICYTEX), Badajoz. The aim of the present work was to characterize those conserved individuals from four different populations based on both an ampelographic description and a molecular analysis. Three vines per individual were studied.