Regulated Salinity Eustress in a Floating Hydroponic Module of Sequentially Harvested Lettuce Modulates Phytochemical Constitution, Plant Resilience, and Post-Harvest Nutraceutical Quality

A mild salinity stress (eustress) may modulate the induction of plant defense system in horticultural crops and synthesis phytochemical components able to enhance resilience, post-harvest performance, nutraceutical quality produce. However, choice correct eustress type dose induce these protective phytochemicals is pivotal avoid potential interference with growth productivity. In order study how green red lettuce (Lactuca sativa L.) plants equilibrate nutritional yield components, we applied iso-osmotic concentrations three different salts (20 mM NaCl, 20 KCl, 13.3 CaCl2, a final total ionic concentration 40 mM) combination two successive harvests floating raft system. The biometric parameters, mineral composition, bioactive compounds, antioxidant activity both cultivars were analyzed. cultivar had superior response concerning traits productivity compared one during first cut but lower content (e.g., ascorbic acid). effect order, independently treatments, demonstrated that at harvest could redirect metabolism by increasing lipophilic (LAA) expense yield, therefore resilience quality; whereas, second harvest, reverted principally tissue expansion. treatments salt did not affect K Mg ion contents further increased LAA resulted only moderate decrease fresh yield. nitrate was reduced when treated NaCl especially CaCl2.