Certified clone and powdery mildew impact rotundone in red wine from <i>Vitis vinifera L.</i> cv. Duras N

Abstract

Aim: Few recent studies have been investigating the effect of clone on aroma compounds. The aim of this research work was to study the impact of certified clones from Vitis vinifera L. cv. Duras N on grape quality and rotundone, a sesquiterpene responsible for peppery aroma which has been reported recently in red wines made from this cultivar. Methods and results:The experimental site consisted of four consecutive rows, each row planted with one of the four certified clones of Duras N (554, 555, 627 and 654). For each clone, measurements were replicated on three experimental units per row. Each experimental unit consisted of twelve continuous vines. Rotundone concentration was measured in wines prepared by microvinification techniques (1-L Erlenmeyer flasks). For both vintages of study, rotundone concentrations were significantly higher in wines from clones 554 and 654 in comparison with clone 555, while clone 627 showed an intermediate level. In 2014, differences in powdery mildew (PM) severity on clusters were identified between the four clones and a positive logarithmic correlation (r 2 = 0.58) was reported on the experimental site between rotundone in wines and PM severity on grapes. Conclusion:Our results found differences in rotundone concentrations in wines made from the four Duras N certified clones. The results also suggested that grapevine defence response to PM could enhance rotundone production in berries. Clonal differences in susceptibility to biotic stress, such as PM, might explain the differences observed in rotundone concentrations between the four studied clones.Significance and impact of the study: Our results may assist grape growers to produce high quality wines with a desired aroma attribute made from Duras N. One should consider planting clone 554 in order to promote high levels of rotundone in wines made from this cultivar.Objectif : Peu d'études récentes ont étudié l'effet du clone sur les composés aromatiques. L'objectif de ce travail de recherche était d'évaluer l'impact des clones certifiés de Vitis vinifera L. cv. Duras N sur la qualité des raisins et la rotundone, un sesquiterpène responsable des arômes poivrés identifié récemment dans les vins élaborés à partir de ce cépage. Méthodes et résultats: Le site expérimental se compose de quatre rangs consécutifs, chacun des rangs étant planté avec l'un des quatre clones certifiés de Duras N (554, 555, 627 et 654). Pour chacun des clones, les mesures ont été répétées sur trois placettes expérimentales par rang, chacune d'entre elle se composant de douze pieds consécutifs. La concentration en rotundone a été mesurée dans des vins élaborés en condition de microvinification (Erlenmeyer d'1 L). Pour les deux millésimes d'étude, les concentrations en rotundone ont été significativement supérieures dans les vins des clones 554 et 654 en comparaison avec le clone 555 alors que le clone 627 a présenté un niveau intermédiaire. En 2014, des différences d'intensité de dégâts d'oïdium ont été mises en évidence sur grappes entre les quatre clones et u...

Fortification and Elevated Alcohol Concentration Affect the Concentration of Rotundone and Volatiles in Vitis vinifera cv. Shiraz Wine

“…However, no elevation in the concentration of rotundone was observed when feeding grapevine leaves with larvae of the light brown apple moth [19]. On the other hand, disease has been associated with rotundone production, with more rotundone observed in Duras grapes with higher severity of powdery mildew [12].…”

“…Rotundone is responsible for the attractive "pepper" character in grape berries and wine, and is especially important for cool-climate Shiraz (Syrah) [6][7][8]. It is possible to manipulate the concentration of this compound in wine by increasing rotundone production in grape berries [8][9][10][11][12][13][14][15][16][17][18][19]. Approximately 10% of the rotundone in grape skins is extracted into the grape berries during fermentation, regardless of starting concentration, so any manipulation that increases the amount of rotundone in grapes will be reflected by an increase in wine.…”

“…The capacity of rotundone production varies amongst different grapevine clones, and is associated with pest/disease stress [4,12]. Under similar growing conditions, Shiraz 2626 clone and Duras 554 and 654 clones have been identified to produce relatively higher concentration of rotundone [4,12].…”

“…Under similar growing conditions, Shiraz 2626 clone and Duras 554 and 654 clones have been identified to produce relatively higher concentration of rotundone [4,12]. Many terpenes are considered as herbivore-induced plant volatiles, and are produced by grapevines as defensive metabolites in response to pests.…”

On-vine grape drying combined with irrigation allows to produce red wines with enhanced phenolic and rotundone concentrations

“…It has been identified in Pinot Noir, Durif, Graciano, Riesling (Herderich et al, 2012) and more recently in other cultivars such as Duras (Geffroy et al, 2014), Gamay (Geffroy et al, 2016), and Malbec, Abouriou (Cullere et al, 2016) grown in France under cool or Atlantic climate conditions. Differences in rotundone concentrations in wines made from four Duras certified clones suggest that rotundone was involved in the vine's natural response to powdery mildew attacks (Geffroy et al, 2015b). While leaf removal strongly reduces rotundone, irrigation enhances its accumulation in berries (Geffroy et al, 2014).…”