Influence of climate change conditions (elevated CO₂ and temperature) on the grape composition of five tempranillo (Vitis vinifera L.) Somatic variants

Abstract

Context and purpose of the study ‐ The current levels of greenhouse gas emissions are expecting to provoke a change on the environmental conditions which, among others, will include a rise of global mean surface temperature and an increment of atmospheric CO2 levels (IPCC, 2014), known as climate change. The response of grapevine (Vitis vinifera L.), one of the most important crops in Europe, from both a cultural and economic point of view, is not completely understood yet and the studies considering the interaction between factors are scarce. Besides, the potential variety of responses among somatic variants needs to be studied in order to be exploited in the avoidance of undesired traits linked to climate change (Carbonell‐Bejerano et al., 2015).

Material and methods ‐ The objective was to determine the impact of an increment of atmospheric CO2 and temperature (both acting independently and combined) on the grape composition of five somatic variants of Tempranillo (CL306, T3, RJ43, 1084 and VN31). Fruit‐bearing cuttings were grown from fruit‐set to maturity (around 22ºBrix) in temperature gradient greenhouses under two temperature regimes (ambient temperature and ambient temperature + 4ºC) in combination with two CO2 levels (400 ppm and 700 ppm).

Results ‐ The evolution of sugars (glucose and fructose) and malic acid, as well as the final levels of anthocyanins and the relation of anthocyanins and sugars indicate that grape ripening will be affected by climate change in different manner among somatic variants. High temperatures increased the degradation of malic acid and raised the accumulation of sugars, meanwhile CO2 levels also promoted the degradation of malic acid especially at maturity. Somatic variants showed differences in the anthocyanin levels at maturity. Total anthocyanins were not dramatically affected by the temperature and CO2 levels assayed. The CL306 and T3 somatic variants were identified as potential candidates for the adaptation of cv. Tempranillo to climate change.