Single plant oenotyping: a novel approach to better understand the impact of drought on red wine quality in Vitis x Muscadinia genotypes

Abstract

Adopting disease-tolerant varieties is an efficient solution to limit environmental impacts linked to pesticide use in viticulture. In most breeding programs, these varieties are selected depending on their abilities to tolerate diseases, but little is known about their behaviour in response to abiotic constraints. In particular, the lack of normalised laboratory scaled fermentation tools hinders an accurate assessment of their potential for wine production, when they are exposed to water scarcity [1,2]. The aim of this study was to evaluate the effect of water deficit on wine analytical characteristics of new disease-tolerant varieties implementing a new design combining single plant phenotyping and oenotyping. Three red fungus-tolerant Muscadinia × Vitis hybrids (G14, 3176N, Artaban) and Syrah (control) were exposed to a wide water deficit gradient over 5 years (2018-2022) in the field. The objective was to monitor short and long-term effects of drought on water and carbon relations at the plant and fruit levels [3,4,5,6], and evaluate their impacts on wine composition during the last year of experiment. For this purpose, grapes from a selection of plants covering a range of response to drought were individually harvested at physiological ripe stage. They were analysed for their contents in major metabolites (primary and secondary) and cations. 900g were stored in trays and deep-frost for subsequent processing using the Vinimag device. This robotised platform was designed to allow standardised red wine processing [7] at single plant level (T=23°C, YAN=160mg/L). Besides oenological parameters, phenolic compounds (hydroxycinnamic acids, anthocyanins, flavanols) and aromas (thiols and precursors) analysis were performed on wines using UHPLC-DAD and a MS/MS detection for aromas. In complement to the observations reported about the effect of water deficit on grape composition at harvest, this experiment provided a new set of data about post-harvest effects of water stress on fermentation processing and wine composition. Collected data highlighted a negative correlation between field water stress and the mean degree of polymerisation (mDP) of flavanols (catechin and epicatechin mainly), as previously observed on grapes [8]. Along with the mDP, acidity and colour parameters were impacted by plant water status. This study demonstrated the interest of a new approach combining both single plant phenotyping and oenotyping to better understand the impact of plant water stress on red wine quality markers (aromas and phenolic compounds).

References

[1] Cesson, A., Ducasse, M.-A., Sanchez, I., Boulet, J.-C., Carrillo, S., Doco, T., Godet, T., Macna, F., Mabille, F., Meudec, E., Nolleau, V., Roi, S., Roy, A., Sachot, S., Schuhmann, A., Sommerer, N., Suc, L., Thouroude, M., Mouret, J.-R., & Poncet-Legrand, C. (2024). 45th  OIV Congress, 14-17 Oct., Dijon, France.

[2] Duley, G.,  Ceci, A.T., Longo, E., Boselli, E., Comp E., (2023) Rev Food Sci Food Safe 1541-4337.13155

[3] De Almeida, L. W., Pastenes, C., Ojeda, H., Torregrosa, L., & Pellegrino, A. (2024). Frontiers in Plant Science, 15, 1405343

[4] De Almeida, L. W., Pellegrino, A., Fontez, B., Torregrosa, L., & Ojeda, H. (2023). Oeno one, 57, 203–218

[5] De Almeida, L. W., Torregrosa, L., Dournes, G., Pellegrino, A., Ojeda, H., & Roland, A. (2023). Journal of Agricultural and Food chemistry, 72(4), 1855–1863

[6] Wilhelm De Almeida, L., Ojeda, H., Pellegrino, A., & Torregrosa, L. (2024). Plant Physiology and Biochemistry, 212, 108774

[7] Ducasse, M.-A., Roy, A., Caboulet, D., Bolandard, P., Cesson, A., Sanchez, I., Sommerer, N., Meudec, E., Flores, D., Poncet-Legrand, C., M., Mouret, J.-R ., Perez, M., Saurin, N., Leborgne, C., Aguera, E.(2024). 45th  OIV Congress, 14-17 Oct., Dijon, France

[8] Ojeda, H., Andary, C., Kraeva, E., Carbonneau, A., & Deloire, A. (2002). American Journal of Enology and Viticulture, 53, 261–267.