Elicitors of Salt Stress Tolerance during Germination and Early Growth of Basil (Ocimum basilicum L.)

Salt stress attenuators assist seed germination by reducing the effects of osmotic and ionic stress, y promoting water uptake, they stabilize enzymes and enhance metabolic tolerance, resulting in higher germination rates and more uniform early development. This study evaluates the effects of applying salt stress attenuators on the germination and seedling formation of O. basilicum as a pre-germination treatment. Two cultivars, Limoncino (tolerant) and Genaro de Menta (sensitive), were subjected to pre-germination treatments combining salt stress with a stress-attenuating agent: no pre-germination treatment and no salt stress; salt stress (6.98 dS m−1 NaCl); hydropriming + salt stress; gibberellic acid (50 mg L−1) + salt stress; salicylic acid (50 mg L−1) + salt stress; ascorbic acid (50 mg L−1) + salt stress. Basil cultivars responded differently to salinity simulated by NaCl (6.98 dS m−1). Limoncino maintained high germination percentage, germination speed index, shoot and root growth, and biomass accumulation under saline conditions, regardless of pre-treatment. In contrast, Genaro de Menta showed reductions in germination speed, root length, and total seedling growth under salinity. Seed pre-treatment with ascorbic acid and salicylic acid attenuated the effects of salinity when applied at 6.98 dSm−1, improving germination speed, root development, and osmotic adjustment in the sensitive cultivar, indicating physiological performance under salt stress. Thus, Limoncino exhibits inherent tolerance to salinity during germination, whereas seed pre-treatment with ascorbic acid (AsA) or salicylic acid (SA) is required to partially restore early growth in the salt-sensitive cultivar Genaro de Menta.