Select vines that transpire less at night.

Water-efficient grape varieties would be a major asset in coping with drought episodes and the increasing water demand driven by climate change. However, it is difficult to reduce water use (transpiration) by plants without compromising their growth. Like other crops, the vine must absorb atmospheric CO₂ to sustain photosynthesis. This absorption occurs on the leaf surface through tiny pores called stomata, which are also responsible for water loss through transpiration. So, how can we reconcile vigorous growth with water savings? Our team focused on nighttime transpiration, when photosynthesis stops and CO₂ uptake through stomata becomes unnecessary. By screening around 200 offspring from a Syrah–Grenache cross, we found that stomata did not fully close at night, causing significant water losses through transpiration—ranging from single to double among the offspring. We identified genomic regions associated with low nighttime transpiration without affecting growth, paving the way for selecting water-efficient and productive varieties.

Article published in Revue des Œnologues (N°172, July 2019)

Référence :

Pantin F, Coupel-Ledru A, Westgeest AJ, Simonneau T (2019)  Adaptation au changement climatique Sélectionner des vignes qui transpirent moins la nuit. Revue des Œnologues 172: 15–18.