IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 New fungus-resistant grapevine varieties display high and drought-independent thiol precursor levels

New fungus-resistant grapevine varieties display high and drought-independent thiol precursor levels

Abstract

The use of varieties tolerant to diseases is a long-term but promising option to reduce chemical input in viticulture. Several important breeding programs in Europe and abroad are starting to release a range of new hybrids performing well regarding fungi susceptibility and wine quality. Unfortunately, little attention is paid by the breeders to the adaptation of these varieties to climatic changes and to the aromatic potential such as thiol precursors. Indeed, varietal thiols (3-sulfanylhexan-ol (3SH) and its acetate or the 4-methyl-4-sulfanylpentan-2-one (4MSP)) are very powerful aromatic compounds in wines coming from odorless precursors in grapes and could contribute to the typicity of such varieties. This study aimed to characterize 6 new resistant varieties selected by INRAE (Floreal, G5 and 3159B for white grapes and Artaban, 3176N and G14 for red grapes) in comparison to Syrah to (i) quantify the thiol precursors in the fruits and to (ii) evaluate the influence of water deficit (WD) imposed on field-grown vines on these molecules. Grapes were picked-up at the arrest of phloem unloading to objectify the sampling at a precise physiological landmark and analyzed by LC-MS/MS. Six thiol precursors were quantified by isotopic dilution across all samples and only 3 were clearly identified and quantified: the glutathionylated (G3SH), cysteinylated (Cys3SH) and one dipeptidic precursors of 3SH (CysGly3SH). For all varieties, G3SH contents represented between 75 and 100% of the aromatic potential, followed by Cys3SH (0-16%) and finally the CysGly3SH (0-13%). The absolute concentrations of G3SH ranged from 31 to 132 µg/kg for white varieties and from 68 to 466 µg/kg for red ones. Surprisingly, 3176N had exceptional G3SH levels that can reach 466 µg/kg which corresponded to nearly 777 µg/L in volume concentration. The pedigree of this variety which includes Grenache as a progenitor could explain the high levels of thiol precursors as observed in the Rosé wines of Provence, a type of wines also characterized by high levels of varietal thiols. Whatever the variety, we did not find marked effects of WD on the contents in thiol precursors when expressed in µg/kg. When expressed in µg/berry to reflect the real impact of WD on rate of metabolite accumulation per organ, 3176N and Artaban showed significant differences between moderate and high WD treatments (p-value < 0.05, less amount of thiol precursors in WD grapes). Analyzing thiol precursors and more generally metabolites of interest in fruits requires to objectify the sampling date at a given physiological stage. This allows deciphering the effects of environmental factors on the accumulation of metabolites at organ or plant level and their consequences in the concentration of the fruit at harvest. In conclusion, resistant varieties seemed to be less impacted by WD than Vinifera ones, which is bode well for the development of these varieties in relation to climate change challenges.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Roland Aurélie1, Wilhelm Luciana2,3,4, Torregrosa Laurent2,3, Dournes Gabriel4, Pellegrino Anne3 and Ojeda Hernán2

1 SPO, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
2 UE Pech Rouge, INRAE, Gruissan, France
3 UMR LEPSE, Montpellier Uni – CIRAD – INRAE – Institut Agro, Montpellier, France
4 UMR AGAP, Montpellier Uni – CIRAD – INRAE – Institut Agro, Montpellier, France  

Contact the author

Keywords

Climate change, water deficit, tolerant varieties, wine quality, thiol precursors

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Current climate change in the Oplenac wine-growing district (Serbia)

Serbian autochthonous vine varieties Smederevka (for white wines) and Prokupac (for rosé and red wines) are the primary representatives of typical characteristics of wines and terroir of numerous wine-growing areas in Serbia. In the past, these varieties were the leading vine varieties, however, as the result of globalization of winemaking and the trend of consumption of wines from widely prevalent vine varieties, they were replaced by introduced international varieties. Smederevka and Prokupac vine varieties are characterized by later time of grape ripening, and relative sensitivity to low temperatures. Climate conditions can be a restrictive factor for production of high-quality grapes and wine and for the spatial spreading of these varieties in hilly continental wine-growing areas.
This paper focuses on the spatial analysis of changes of main climate parameters, in particular, analysis of viticultural bioclimatic indices that were determined for the purposes of viticulture zoning of wine-growing areas in the period 1961-2010, and those same parameters determined for the current, that is, referential climate period (1988-2017). Results of the research, that is, analysis of climate changes indicate that the majority of examined climate parameters in the Oplenac wine-growing district improved from the perspective of Smederevka and Prokupac vine varieties. These studies of climate conditions indicate that changes of analyzed climate parameters, that is, bioclimatic indices will be favorable for cultivation of varieties with later grape ripening times and those more sensitive to low temperatures, such as the autochthonous vine varieties Smederevka and Prokupac, therefore, it is recommended to producers to more actively plant vineyards with these varieties in the territory of the Oplenac wine-growing district.

Towards adaptation to climate change in Rioja: Quality evaluation of wines obtained from Grenache x Tempranillo selections

The wine sector is of great relevance and tradition in Mediterranean countries, however, it may be most susceptible to climate change. In recent years, wine production is facing changes worldwide, both at environmental as well as commercial levels, due to global warming and the shift in consumers’ preferences. Wine growers and wine makers are in search of solutions that allow to face these new challenges. One of the most promising initiatives in the long term is the introduction of new plant materials, specifically intraspecific hybridizations between premium varieties that may improve traditional germplasm in its adaptation to climate change. These inter-varietal crosses have the potential to generate quality wines, whilst maintaining the regional typicity, and constitute an attractive alternative for the consumer due to their sensory attributes. In this study, we have evaluated wines from 29 intraspecific Garnacha x Tempranillo hybrids in two different locations, with the aim to assess their oenological potential and sensory attributes. Thirteen of the selections were white and 16 were red. Microvinifications were conducted with two or three replications depending on grape availability. Conventional oenological parameters were determined for all wines. The sensory evaluation and hedonic scores were given by five experts. Red selections obtained higher quality scores than white ones. Among the white selections with higher quality scores, GT-41 Varea and GT-159 Varea outstand, due to their high total acidity and high malic acid content. Regarding red selections, GT-57 Varea and GT-57 UR were perceived as higher in quality, highlighted for their moderate alcoholic and high anthocyanin content. Our results indicate that intraspecific hybridization may be a powerful tool for adapting traditional cultivars to climate change in Rioja.

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.

Grapevine sugar concentration model in the Douro Superior, Portugal

Increasingly warm and dry climate conditions are challenging the viticulture and winemaking sector. Digital technologies and crop modelling bear the promise to provide practical answers to those challenges. As viticultural activities strongly depend on harvest date, its early prediction is particularly important, since the success of winemaking practices largely depends upon this key event, which should be based on an accurate and advanced plan of the annual cycle. Herein, we demonstrate the creation of modelling tools to assess grape ripeness, through sugar concentration monitoring. The study area, the Portuguese Côa valley wine region, represents an important terroir in the “Douro Superior” subregion. Two varieties (cv. Touriga Nacional and Touriga Franca) grown in five locations across the Côa Region were considered. Sugar accumulation in grapes, with concentrations between 170 and 230 g l-1, was used from 2014 to 2020 as an indicator of technological maturity conditioned by meteorological factors. The climatic time series were retrieved from the EU Copernicus Service, while sugar data were collected by a non-profit organization, ADVID, and by Sogrape, a leading wine company. The software for calibrating and validating this model framework was the Phenology Modeling Platform (PMP), version 5.5, using Sigmoid and growing degree-day (GDD) models for predictions. The performance was assessed through two metrics: Roots Mean Square Error (RMSE) and efficiency coefficient (EFF), while validation was undertaken using leave-one-out cross-validation. Our findings demonstrate that sugar content is mainly dependent on temperature and air humidity. The models achieved a performance of 0.65

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.