The effect of drought memory on grapevine physio logical responses to water deficit and recovery

Abstract

To cope with water stress, grapevine developed efficient adaptation mechanisms to transfer water from roots to shoots, mediated by an efficient stomatal control of transpiration. Each variety has a specific water use regulation response under drought, which is important to study. In the present work, we explored the influence of the field-grown genotypes’ drought memory in the drought-response phenotype of their vegetative progenies, in Trincadeira (isohydric) and Castelão (anisohydric) cultivars under a drought event followed by recovery. These progenies were subjected to full irrigation (FI) and non-irrigation (NI) for five years in the field, and their progenies were in grown in a glasshouse and subjected to a well-watered and a water- stress treatment, followed by recovery. NI progenies from both cultivars had improved gas exchange parameters, better total plant hydraulic conductance under drought, and faster recovery than FI progenies. Nocturnal transpiration was affected both by progeny and treatment. Leaf wax content was significantly enhanced by WS both in FI and NI progenies, but it was higher in NI progenies. Although isohydric and anisohydric genotypes exhibited different drought acclimation responses due to their inner genetic behavior, their underlying hydraulic, stomatal and photosynthetic regulatory mechanisms were also affected by historical origin.