Water Deficit and Rehydration Reveal Genotypic Differences in Apple Tree Physiological Performance

Area of Science:

• Horticulture
• Plant Physiology
• Agricultural Science

Background:

• Apple (Malus domestica) is a vital global fruit crop.
• Water deficit significantly impacts apple productivity.
• Genotype-specific responses to water stress are crucial for resilience.

Purpose of the Study:

• To assess physiological responses of eight apple genotypes to water deficit and rehydration.
• To identify apple genotypes with enhanced water deficit tolerance.

Main Methods:

• Short-term water deficit (14 days) and rehydration (7 days) applied to container-grown apple genotypes.
• Evaluated physiological parameters: pigment content, gas exchange, chlorophyll fluorescence, water use efficiency, and leaf water status.

Main Results:

• Water deficit negatively impacted all physiological parameters across genotypes.
• Significant genotypic variability observed in responses to water deficit.
• Genotypes 'HL 2350' and 'B11' exhibited greater physiological stability under stress compared to 'Idared' and 'Rubinstep'.
• Rehydration led to partial recovery, but physiological levels often remained below control.

Conclusions:

• Substantial genotypic variation exists in apple's physiological response to short-term water deficit.
• Findings offer insights for breeding water-deficit-resilient apple varieties.
• Further field studies are needed to confirm agronomic relevance of observed differences.