Genetic Architecture of Responses to Water Deficit in Grapevine

In this study, quantitative genetic analyses were conducted to identify genomic regions involved in grapevine responses to water deficit. Using diverse scion and rootstock genotypes, QTL mapping revealed loci associated with transpiration rate, stomatal regulation, hydraulic conductivity, water extraction capacity, and water use efficiency. Distinct QTLs were found for baseline transpiration and its acclimation under water stress, as well as for biomass accumulation and water use efficiency, indicating partially independent genetic controls. These findings suggest that improving water use efficiency without compromising productivity is feasible and provide valuable targets for breeding grapevine varieties better adapted to drought conditions.