Theoretical basis of protocols for seed storage.

Area of Science:

• Agricultural Science
• Plant Physiology
• Seed Biology

Background:

• Current seed storage protocols lack consideration for species-specific chemical composition, seed physiological status, and water's physical state.
• Understanding these factors is crucial for enhancing long-term seed viability and conservation efforts.

Purpose of the Study:

• To determine the optimal moisture content for long-term seed storage by investigating the relationship between seed physiology, water status, and longevity.
• To identify specific relative humidity thresholds for key physiological processes in seeds.

Main Methods:

• Assessed physiological status of seeds from five species via oxygen uptake and deterioration rates.
• Characterized the physical status of water using water sorption isotherms.
• Correlated physiological changes with specific relative humidity levels.

Main Results:

• Each species exhibited unique moisture contents for the onset of respiration, chemical reactions, and accelerated aging.
• Physiological activities and water status changes occurred at distinct relative humidities: 91% (respiration), 27% (thermal-chemical reactions), and 19% (optimum longevity).
• Observed correlations between seed lipid content and moisture content thresholds for physiological events.

Conclusions:

• Seed longevity is significantly influenced by moisture content and relative humidity.
• Equilibrating seeds to a relative humidity between 19% and 27% is proposed as an optimal strategy for long-term seed storage.
• This approach accounts for species-specific physiological responses to moisture, improving upon existing general protocols.