Genetic variability of descriptors for grapevine berry acidity in Riesling, Gewürztraminer and their progeny

Abstract

Background and Aims The acidity of harvested grapevine berries is likely to decrease in the future because of increasing temperature during grape ripening. The aim of the study was to evaluate the genetic variability of berry acidity descriptors in progeny from a Riesling × Gewürztraminer cross. Methods and Results The ripening process for the parent cultivars was monitored over three growing seasons; berries from Riesling had a higher tartaric acid concentration than that from Gewürztraminer, and a similar difference was observed for malic acid. A statistical model describing the decline in malic acid concentration over time was fitted to the data. With this model, the parameter that best characterised the two genotypes was the asymptotic minimum value of malic acid concentration per g of berry dry matter. In addition, the rate of decrease of malic acid was constant across years when thermal‐time scales were used. Using samples of green berries at veraison and samples picked 230 degree days after veraison (mean temperature, base 10°C), 120 genotypes from a Riesling × Gewürztraminer progeny were compared over 3 years in the vineyard and segregations for all the berry acidity descriptors were described. Conclusions A significant genotypic variability was observed for the concentration of malic and tartaric acids but also for the estimated cationic content of the berries for the same developmental stage. No genotypes, however, were detected, with a concentration of total malic and tartaric acid significantly higher than that of Riesling. Significance of the Study These results show that berry acidity descriptors are heritable traits that can be manipulated in breeding programs.

A grapevine cytochrome P450 generates the precursor of wine lactone, a key odorant in wine

“…The sampling date was determined for each genotype as the date when a cumulative heat sum of 350 degree-days (calculated with maximum temperatures, base temperature = 10°C) after veraison was reached. This procedure was validated previously for assessing genotypic differences for sugar accumulation capacity (Duchêne et al, 2012b) and berry acidity (Duchêne et al, 2014). Some of the berries were used for sugar and acid analysis and a sample was frozen at À20°C before HPLC analysis.…”

Effect of drying on tartaric acid and malic acid in Shiraz and Merlot berries

“…Most vine growing regions, however, will require agronomic and varietal adaptations (Hannah et al , Keller and Shrestha , van Leeuwen et al , Schultz ). Hence, it is important to understand better berry physiology of different cultivars under abiotic stresses to provide physiological traits for breeders to enable the breeding of cultivars adapted better to future climatic conditions, for example high acidity and low sugar (Duchêne et al , Duchêne ).…”

“…In the ripening berry it is currently believed that little TA degradation takes place (DeBolt et al , Shangguan et al ), which is why cultivars with a high natural content in TA are considered to be better adapted to high temperature and hence future climatic conditions. A naturally high TA content appears thus to represent an important selection criterion for new cultivars better adapted to higher temperature (Duchêne et al ). Some older studies conducted with 14 C, however, show that there is a tartrate turnover or respiration in ripening berries (Drawert and Steffan , Takimoto et al ).…”

How can grapevine genetics contribute to the adaptation to climate change?

“…High temperatures accelerate the decrease of grape acidity, mainly because of a faster degradation of malic acid (Buttrose et al, 1971;Kliewer, 1971;Sweetman et al, 2014). The comparison between different grape growing regions (Barnuud et al, 2014b) or vintages (Duchêne et al, 2014a;Neethling et al, 2012) confirms this result. Varieties whose berries contain high quantities of tartaric acid should be less sensitive to climate change (Shiraishi, 1995) because the quantity of tartaric acid per berry is stable during berry ripening (DeBolt et al, 2008).…”