Terroir 2020 banner
IVES 9 IVES Conference Series 9 The dynamics of δ13C and δ18O in musts during berries development

The dynamics of δ13C and δ18O in musts during berries development

Abstract

Aim: Many processes or reactions that occur in plants involved isotopic discrimination. Water availability, for example, affects the isotopic ratio of carbon (δ13C) and oxygen (δ18O). In viticulture, δ13C is used in experiments related to water relations and irrigation in vineyards. δ18O is used much less but it could be a good complement to δ13C. The aim of this study was to generate knowledge on how these isotopic ratios, measured in musts, could help to better understand the water behavior of grape varieties. 

Methods and Results: The present work was carried out in 2019 with a set of seven varieties selected to monitor the aforementioned ratios in musts obtained during berries development: three of them red (Bobal, Tinto Velasco and Syrah), managed with irrigation, and the other three white (Airén, Malvar and Albillo Real) kept without irrigation; the seventh, Tempranillo, was managed with or without irrigation. 

Monitoring the dynamics of isotope ratios was undertaken through sampling of grapes carried out periodically, from shortly before closing cluster to maturity. In obtained musts, δ13C and δ18O were determined by mass spectrometry of isotope ratios.

The small changes observed between samples in δ13C in a specific variety did not seem to follow any pattern. In most cases, the comparisons of means performed showed no significant differences between samples. However, differences were observed between the two management systems: irrigated and rainfed; in dry conditions, with the stomatal closure, 13C isotopic discrimination declined during photosynthesis, and the ratio then increased.

This was not so with δ18O, where the comparisons of means always showed significant differences between samples. Dynamics of δ18O seemed to adapt, in this case, to a double curve pattern (cubic polynomial): the intense increase in the ratio of the first stages of fruit development was followed by a phase of slight decline, which lasted up to 15 or 20 days before harvest, at which point the ratio increased again. There were both inter-varietal and between management system differences: musts in early harvest varieties showed higher δ18O values than late varieties, while the isotopic enrichment was lower for this isotopic ratio in irrigated vines.

Conclusions:

Differences in the narrow margin in which δ13C values of the grapes are maintained throughout their development seemed to respond more to the crop management practice than to the variety. However, the notable changes in δ18O values seem to be due to a complex mechanism that involves the discharge of water in the grapes from the phloem at beginning of ripening and the loss of water due to transpiration through the skin.

Significance and Impact of the Study: In the search for the genotypes with the highest water efficiency that effectively respond to the proliferation and dilation of drought periods that are expected in many regions, it is urgent to explore the existing genetic variability. In this sense, δ13C and δ18O could be useful tools to take into account in any research related to water use by cultivars at physiological or agronomic levels.

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Adelaida Mena Morales*, Juan Luis Chacón Vozmediano, Rosa Mª Sánchez-Gil Jimeno, Jesús Martínez Gascueña

Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal de Castilla-La Mancha (IRIAF), IVICAM, Ctra. Toledo-Albacete s/n, 13700 Tomelloso, Ciudad Real, Spain

Contact the author

Keywords

Grapevine, genotypes, musts, δ13C dynamics, δ18O dynamics, IRMS

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.