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IVES 9 IVES Conference Series 9 Drought responses in Chardonnay and Sauvignon blanc grapevine cultivars: Mechanistic insights and varietal contrasts

Drought responses in Chardonnay and Sauvignon blanc grapevine cultivars: Mechanistic insights and varietal contrasts

Abstract

This study explored the responses of Chardonnay and Sauvignon blanc grapevine cultivars to water deficit across four years, uncovering their shared patterns and distinctive coping mechanisms. The research was conducted in a commercial vineyard located in Isla de Maipo, Chile. Various characterization approaches were employed including plant water potentials (Y), gas exchange measurements, shoot vulnerability curves, productivity assessments, and leaf cell water relations. Linear mixed models and sensitivity analyses were performed using various statistical methods to evaluate cultivar responses to water deficit. As the water deficit progressed, both cultivars displayed a parallel reduction in stomatal conductance, leaf turgor, and increased shoot embolism. Moreover, both cultivars exhibit a sigmoid decrease in yield as Yleaf declined, highlighting a 50% productivity reduction corresponding to a 50% reduction in stomatal conductance. However, Chardonnay demonstrated higher drought tolerance, achieving more negative Yleaf values during water deficit, with leaf turgor loss occurring at a lower Y threshold. Furthermore, differences in Yleaf between the cultivars stemmed from their distinct drought-coping mechanisms. Chardonnay employed osmotic adjustment to facilitate water movement and maintain turgor, while Sauvignon blanc relied on elastic adjustment to sustain elevated leaf water content. Sensitivity analysis suggests the limited impact of osmotic adjustment on Chardonnay’s Yleaf variability, emphasizing its function as a delayed response to water stress. Conversely, Sauvignon blanc’s higher bulk elastic modulus influences Yleaf fluctuations more prominently, promoting rapid rehydration under water scarcity. These mechanisms determined Yleaf magnitudes, with Sauvignon blanc exhibiting lower stress levels than Chardonnay.

DOI:

Publication date: June 13, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Felipe Suárez-Vega1*, Felipe Torres-Pérez1, Bastián Silva-Gutiérrez1, Benjamín Velázquez-Pizarro1, J. Antonio Alcalde1, Alonso G. Pérez-Donoso1*

1 Departamento de Fruticultura y Enología. Pontificia Universidad Católica de Chile

Contact the author*

Keywords

Grapevine cultivars, water deficit, drought tolerance, osmotic adjustment, bulk elastic modulus

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

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