South Africa Wine Research Projects

2. VITICULTURE RESEARCH COMPLETED PROJECT

GRAPEVINE’S RESPONSE TO WATER STRESS USING DIFFERENT SCION/ROOTSTOCK COMBINATIONS

IWBT 18-01 Prof Melané Vivier, South African Grape and Wine Research Institute,

Stellenbosch University Project completed: 2023

AIM AND INDUSTRY RELEVANCE: Grapevine scion cultivars, as well as rootstocks, display different levels of tolerance to water stress. This project aimed to assess grapevine response(s) to water deficit stress at molecular and physiological levels in potted vines via computational analysis to identify biomarkers in grapevines. Quantification of transcriptional responses to water stress and various devices and sensors were assessed for their sensitivity and precision in monitoring grapevine responses to water stress alongside established reference techniques. The study confirmed that the grapevine’s response to water stress is intricate and is influenced by the timing and severity of stress and genotype. Genotype differences in rootstock and scion responses were evident. The grapevines exhibited high adaptability, with acclimation appearing to be a crucial mechanism employed by grapevines in response to recurring stress events. It was found that young vines showed varied responses to stress that lessen with maturity. Molecular markers were verified to be working to respond to water stress. The potted vines provided an optimal environment for active drying experiments, and the population thereof will serve as an asset to educate, train and study water stress in grapevines using active drying experiments, molecular markers and sensor technology. Future work that expands on these results will inform vineyard management tools like cultivar and rootstock selection as an adaptation strategy.

SOUTH AFRICA WINE RESEARCH 2024

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