Carbon trade-offs in the fruits of fungus-tolerant Muscadinia × Vitis hybrids exposed to water deficit.

Adopting disease-tolerant grapevines is an efficient option to implement a smarter management strategy limiting the environmental impacts linked to pesticide use. However, little is known on their production of fruit metabolites regarding expected future climate fluctuations, such as increased water shortage. Moreover, previous studies about how water deficit impacts grape composition, lack accuracy due to imprecise timing of fruit sampling.

New Fungus-Resistant Grapevine and L. × Derivative Hybrids Display a Drought-Independent Response in Thiol Precursor Levels.

The use of new disease-resistant grapevine varieties is a long-term but promising solution to reduce chemical inputs in viticulture. However, little is known about water deficit effects on these varieties, notably regarding berry composition. The aim of this study was to characterize the primary metabolites and thiol precursors levels of 6 fungi-resistant varieties and Syrah.

The reduction of plant sink/source does not systematically improve the metabolic composition of Vitis vinifera white fruit.

The quality of wine grapes depends on the balance between primary and secondary metabolites. Unlike many perennial crops that accumulate starch in the fruits before ripening, the non-climacteric grapes ripe with no previous carbon reserves. Based on the assumption that fruit carbon sink is limiting metabolite accumulation in grapes, bunch thinning is performed to limit plant Sink/Source (S/S).

A functional-structural plant model that simulates whole- canopy gas exchange of grapevine plants (Vitis vinifera L.) under different training systems.

Background And Aims: Scaling from single-leaf to whole-canopy photosynthesis faces several complexities related to variations in light interception and leaf properties. To evaluate the impact of canopy strucuture on gas exchange, we developed a functional-structural plant model to upscale leaf processes to the whole canopy based on leaf N content. The model integrates different models that calculate intercepted radiation, leaf traits and gas exchange for each leaf in the canopy.

Disease Resistant Bouquet Vine Varieties: Assessment of the Phenolic, Aromatic, and Sensory Potential of Their Wines.

The search for grape varieties resistant to diseases and to climatic changes notably concerns the wine industry. Nine monovarietal wines from new red grape varieties resistant to cryptogamic diseases (downy and powdery mildews) were evaluated in terms of their total phenolic, anthocyanin and proanthocyanidin contents, anthocyanin profile, volatile composition, and sensory attributes. Thus, the question remains, will these hybrid grapes (≥97.

Impact of agronomic practices on grape aroma composition: a review.

Aroma compounds are secondary metabolites that play a key role in grape quality for enological purposes. Terpenes, C -norisoprenoids, phenols, and non-terpenic alcohols are the most important aroma compounds in grapes and they can be found as free volatiles or glycoconjugated (bound) molecules. The non-volatile glycosylated group is the largest, and it is present in all varieties of Vitis vinifera (L.

L. Fruit Diversity to Breed Varieties Anticipating Climate Changes.

The wine industry is facing critical issues due to climate changes since production is established on very tight Genotype × Environment interaction bases. While, some cultivation practices may reduce adverse effects of abiotic stresses on the vines, e.g.

Drought will not leave your glass empty: Low risk of hydraulic failure revealed by long-term drought observations in world's top wine regions.

Grapevines are crops of global economic importance that will face increasing drought stress because many varieties are described as highly sensitive to hydraulic failure as frequency and intensity of summer drought increase. We developed and used novel approaches to define water stress thresholds for preventing hydraulic failure, which were compared to the drought stress experienced over a decade in two of the world's top wine regions, Napa and Bordeaux. We identified the physiological thresholds for drought-induced mortality in stems and leaves and found small intervarietal differences.

The Microvine, a plant model to study the effect of vine-shoot extract on the accumulation of glycosylated aroma precursors in grapes.

Background: The Microvine plant model displays unique reproductive organ behavior and is suitable for grapevine fruit physiological studies, allowing one to undertake studies up to five times more rapidly than the current situation with grapevines. Recently, vine-shoot aqueous extracts, which have an interesting phenolic and aroma composition, have been proposed as viticultural biostimulants, since their post-veraison foliar application to grapevines impacts the wine aroma profile. Using Microvines, the aim of this study was to determine the effect of vine-shoot extract foliar application on 21 stages of grape development.

Effect of irrigation and timing and type of nitrogen application on the biochemical composition of Vitis vinifera L. cv. Chardonnay and Syrah grapeberries.

This study reports the effect of different doses of nitrogen applied to soil and/or leaves of Syrah and Chardonnay grapevines in the Languedoc-Roussillon (France) over two years. In 2011, nitrogen treatment involved both foliar urea sprayings and soil application at two different levels, with two controls - irrigated without nitrogen and no irrigation nor nitrogen. In 2012, the same grapevines received either soil or foliar nitrogen using the same controls.

Glycosidic aroma precursors of Syrah and Chardonnay grapes after an oak extract application to the grapevines.

Syrah and Chardonnay grapevines were treated with an oak extract in order to determine the effect on glycosidic aroma precursors. Grapevines were treated at three different timings of the veraison (treatment 1, 2 and 3). Aglycons were obtained by enzymatic hydrolysis, and these were identified and quantified by means of gas chromatography-mass spectrometry (GC-MS).

A leaf gas exchange model that accounts for intra-canopy variability by considering leaf nitrogen content and local acclimation to radiation in grapevine (Vitis vinifera L.).

Understanding the distribution of gas exchange within a plant is a prerequisite for scaling up from leaves to canopies. We evaluated whether leaf traits were reliable predictors of the effects of leaf ageing and leaf irradiance on leaf photosynthetic capacity (V(cmax) , J(max) ) in field-grown vines (Vitis vinifera L). Simultaneously, we measured gas exchange, leaf mass per area (LMA) and nitrogen content (N(m) ) of leaves at different positions within the canopy and at different phenological stages.