Selecting Aragonez Genotypes Able to Outplay Climate Change-Driven Abiotic Stress

Area of Science:

• Plant Science
• Viticulture
• Climate Change Adaptation

Background:

• Portugal's viticulture faces increasing threats from high temperatures and extreme drought due to climate change.
• Adapting grape varieties to these abiotic stresses without compromising wine quality and yield is a significant challenge.
• Intravarietal variability offers a potential avenue for selecting climate-resilient genotypes.

Purpose of the Study:

• To develop and apply an innovative selection approach for identifying Aragonez (Tempranillo) clones with enhanced abiotic stress tolerance.
• To evaluate the impact of stress tolerance selection on yield and must quality characteristics.
• To investigate the molecular basis of stress tolerance through gene expression analysis.

Main Methods:

• Phenotypic selection of 255 Aragonez (Tempranillo) clones over three years based on leaf temperature under drought and heat stress.
• Assessment of yield and must quality parameters (pH, acidity, °Brix, anthocyanins).
• Gene expression analysis using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) in selected tolerant and sensitive genotypes.

Main Results:

• A group of Aragonez (Tempranillo) genotypes exhibiting increased tolerance to abiotic stress was successfully selected.
• Selected clones maintained typical must quality and yield comparable to the variety's average.
• Key gene transcripts associated with abiotic stress tolerance were identified in tolerant clones, serving as potential molecular markers.

Conclusions:

• The developed selection methodology effectively identifies Aragonez (Tempranillo) genotypes better adapted to climate change-induced abiotic stresses.
• This approach allows for the exploitation of intravarietal variability to mitigate climate change impacts on viticulture.
• Identified molecular markers can aid future breeding programs for developing climate-resilient grape varieties.