Hydration and dehydration cycles for enhanced soursop (Annona muricata) seedling quality and seedling drought stress resistance

• Published in: New forests 2024-11, Vol.55 (6), p.1843-1861
• Main Authors: Freitas, Rafael Silva, dos Santos-Júnior, José Laurindo, dos Santos Luz, Alan Feitosa, da Silva, Elizamar Ciríaco
• Format: Article
• Language: English
• Subjects: Agricultural ecosystems; Annona muricata; Biomedical and Life Sciences; Dehydration; Drought resistance; Dry matter; Drying; Environmental stress; Forestry; Germination; Hydration; Life Sciences; Parameter sensitivity; Plant layout; Plant stress; Seedlings; Seeds; Survival; Water deficit; Water quality
• ISSN: 0169-4286; 1573-5095
• DOI: 10.1007/s11056-024-10062-w

The seedling stage is crucial for plant establishment in natural and agricultural ecosystems. Some species have reduced germination rates and are sensitive to environmental stresses, making this stage even more critical. In this study, we employed sublethal stress levels in seeds to enhance germination responses and increase survival of seedlings susceptible to water deficiency. Hydration and dehydration cycles in seeds were applied to investigate their effects on germination parameters and subsequent seedling performance under water deficit conditions. The time of hydration and dehydration was based on triphasic imbibition and drying curves and applied up to three times prior germination. Results revealed increased germination rate (%G) and decreased time to reach 50% germination (T 50 ) after hydration and dehydration cycles. Additionally, cyclically treated seeds produced seedlings with a higher survival rate under water deficit, faster growth rates, and greater dry matter production. The Dickson quality index and drought tolerance indices improved, while the stress susceptibility index decreased. These findings indicate that hydration and dehydration cycles in the seeds induce changes in the seedlings, modifying their basal stress response levels and contributing to the production of hardier seedlings capable of coping with environmental stresses. These responses are anchored in plant stress memory acquired after sublethal exposure to stress levels.