Minority grapevine varieties as climate change adaptation strategy: Exploring heat tolerance plasticity

Abstract

Climate change is increasing average temperatures and intensity and frequency of extreme events such as heat waves. Productivity declines and plant damage due to those changes are already described for several majority varieties, especially in the Mediterranean basin. Less explored minority varieties can arise as alternatives due high heat tolerance, or for having high acclimation potential to heat. We evaluated the heat tolerance after acclimation in three summer thermic environments of four Spanish varieties: two majority (‘Tempranillo’, ‘Airén’) and two minority (‘Jarrosuelto’, ‘Morate’). Summer thermic environments differed in average temperature, and length of the warm period. Varieties differed in heat tolerance and its plasticity due to the acclimation to the environments. Within the majority varieties, ‘Tempranillo’ showed low heat tolerance and moderate plasticity in heat tolerance highlighting its susceptibility to climate change. ‘Airén’ had slightly higher tolerance than ‘Tempranillo’ and certain adaptation capacity to environments. Within the minority, ‘Jarrosuelto’ had high tolerance to heat events but low heat tolerance plasticity. ‘Morate’ was the variety with highest heat tolerance plasticity, indicating its strong adaptive potential. Majority varieties displayed susceptibility to heat events and global warming negative effects. However, minority varieties can offer solutions either by having high tolerance to heat or by having high acclimation.