GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 From average to individual fruit, a paradigm shift for accurate analysis of water accumulation and primary metabolism in developing berries

From average to individual fruit, a paradigm shift for accurate analysis of water accumulation and primary metabolism in developing berries

Abstract

Context and purpose of the study ‐ Presentknowledge about grape development is mainly driven by the premise that a typical berry would follow the same kinetics as the population average, the principal challenge being to gather representative samples. In this frame, the elaboration of harvest quality directly reflects the impact of the GenotypexEnvironment interaction on fruit metabolism. Much energy is then being devoted to identifying the sites that regulate grape metabolism, upon screening more and more genes and metabolites, and developing virtual berry models simulating sugar and water accumulation in the future harvest. Nevertheless, successive physiological stages never coexist in a fruit and one may wonder whether the “average physiological stage” paradigm does not inevitably lead to a dead end. The strict foundations of berry developmental biology are critically revisited here.

Material and methods – Disparate literature data on the intensity and duration of the second growth period were re‐interpreted, validated and clarified, upon non‐destructive analysis of single berry firmness and growth, on different cultivars in the experimental vineyard of Supagro, as well as on microvines grown in greenhouses. Organic acids and sugars were measured by HPLC on thousands individual berries of Syrah, Pinot and Zinfandel.

Results ‐ Previously unsuspected sub‐periods emerged from the developmental patterns of sugar, water and malic acid flows on single berries, metabolic fluxes and kinetic data being noticeably stable among all investigated cultivars. Berries accumulated sugars at nearly constant volume during the first week following softening, indicating intense xylem back‐flow at this stage. This first period of ripening was also characterized by a net malic acid/4 hexoses exchange consistent with the operation of a sucrose/H+ exchanger at the tonoplast membrane, in usual conditions and genotypes. Aerobic fermentation and vacuolar proton pumps were induced later, while vacuolar malic acid was progressively exhausted, without compromising sugar and water accumulation. As a matter of fact, phloem unloading definitively stopped 28 days after softening. It clearly appeared that the individual fruit develops in a far more determined, reproducible and finally intelligible way than has been predicted so far, based on average samples.New phenotyping procedures were consequently designed for genetic studies, improving heritability and QTLs detection.Switching from fruit genomics and physiology to harvest quality requires a real change in scale, from the fruit to the population. The determinant role of berries asynchrony within the population can’t be ignored any longer, but the impact of the GxE interaction on the population structure essentially remains terra incognita. 

DOI:

Publication date: June 19, 2020

Issue: GiESCO 2019

Type: Article

Authors

Rezk SHAHOOD (1), Stefania SAVOI (2), Antoine BIGARD (2), Laurent TORREGROSA (2), Charles ROMIEU (2)

(1) General Commission for Scientific Agricultural Research, Latakia, Syria
(2) AGAP, Montpellier University, CIRAD, INRA, Montpellier SupAgro, Montpellier, France

Contact the author

Keywords

grape, berry development, development asynchronism, metabolism, ripening

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Regulated deficit irrigation and crop load interaction effects on grape heterogeneity

Aim: To investigate the interaction effects between irrigation and crop load and the resulting impact on grape heterogeneity within a Geographical Indication in South Australia. 

Methods and Results: Cabernet Sauvignon grapes were sampled at the time of harvest from the Coonawarra

Impact of yeast derivatives to increase the phenolic maturity and aroma intensity of wine

Using viticultural and enological techniques to increase aromatics in white wine is a prized yet challenging technique for commercial wine producers. Equally difficult are challenges encountered in hastening phenolic maturity and thereby increasing color intensity in red wines. The ability to alter organoleptic and visual properties of wines plays a decisive role in vintages in which grapes are not able to reach full maturity, which is seen increasingly more often as a result of climate change. A new, yeast-based product on the viticultural market may give the opportunity to increase sensory properties of finished wines. Manufacturer packaging claims these yeast derivatives intensify wine aromas of white grape varieties, as well as improve phenolic ripeness of red varieties, but the effects of this application have been little researched until now. The current study applied the yeast derivative, according to the manufacture’s instructions, to the leaves of both neutral and aromatic white wine varieties, as well as on structured red wine varieties. Chemical parameters and volatile aromatics were analyzed in grape musts and finished wines, and all wines were subjected to sensory analysis by a tasting panel. Collective results of all analyses showed that the application of the yeast derivative in the vineyard showed no effect across all varieties examined, and did not intensify white wine aromatics, nor improve phenolic ripeness and color intensity in red wine.

Yield prediction assessment before bloom and at veraison in a cv. Airén high yielding vineyard in Toledo (La Mancha, Spain)

Anticipation in the possible responses of grapevines to environmental variations is key to adjust field work in view of a more effective management. This idea has been the driving force behind the current work, which seeks to understand the interaction patterns of the vine with its habitat throughout the growing cycle.

The Pampa and the vineyard: gaucho´s natural and symbolic aspects in the identity´s constitution of “Vinhos da Campanha”’s terroir – RS/Brasil

The wine region of “Vinhos da Campanha” is located in southern Brazil, on the Uruguay borderline. The colonization’s process in the region was characterized by territorial disputes between Portuguese

Mechanisms involved in the heating of the environment by the aerodynamic action of a wind machine to protect a vineyard against spring frost

One of the main consequences of global warming is the rise of the mean temperature. Thus, the heat summation by the plants begins sooner in the early spring, and by cumulating growing degree-days, phenological development tends to happen earlier. However, spring frost is still a recurrent phenomenon causing serious damages to buds and therefore, threatening the harvests of the winegrowers. The wind machine is a solution to protect fruit crops against spring frost that is increasingly used. It is composed of a 10-m mast with a blowing fan at its peak. By tapping into the strength of the nocturnal thermal inversion, it sweeps the crop by propelling warm air above to the ground. Thus, stratification is momentarily suppressed. Furthermore, the continuous action of the machine, alone or in synergy, or the addition of a heater allow the bud to be bathed in a warmer environment. Also, the punctual action of the tower’s warm gust reaches the bud directly at each rotation period. All these actions allow the bud to continuously warm up, but with different intensities and over a different period. Although there is evidence of the effectiveness of the wind machines, the thermal transfers involved in those mechanisms raise questions about their true nature. Field measurements based on ultrasonic anemometers and fast responding thermocouples complemented by laboratory measurements on a reduced scale model allow to characterize both the airflow produced by the wind machine and the local temperature in its vicinity. Those experiments were realized in the vineyard of Quincy, in the framework of the SICTAG project. In the future paper, we will detail the aeraulic characterization of the wind machine and the thermal effects resulting from it and we will focus on how the wind machine warms up the local atmosphere and enables to reduce the freezing risk.