Effects of Abscisic Acid (ABA), Gibberellic Acid (GA3), and Polyethylene Glycol (PEG) Seed Priming on the Growth of Oryza Sativa L. Under Salinity Stress

Abstract

Soil salinity is a major abiotic stress limiting crop yield and productivity. Rice is a global staple food; however, it is the most sensitive to salinity among important cereal crops. Seed priming is a technique that enhances the growth traits of crops given stress conditions. The present study aims to assess the growth performances of NSIC Rc 160, NSIC Rc 534, IR29, IR74, and Pokkali subjected to ABA, GA3, and PEG seed priming at 9 dS/m salinity level. The analysis of the growth performance at the seedling stage was carried out in a hydroponic system using a salinized nutrient solution. The standard evaluation system (SES) scoring revealed that NSIC Rc 160 scored the lowest (x̄ = 3.3 ± 0.47, tolerant) in PEG-primed and highest (x̄ = 7.30 ± .47, sensitive) in unprimed setups. Similarly, these were observed in the lowest and highest values (x̄ = 3.0, tolerant, and x̄ = 7.0, sensitive, respectively) of NSIC Rc 534. Moreover, the Two-way ANOVA and Tukey HSD post hoc test revealed that both test cultivars have significantly improved growth than IR29 but were not significantly different with IR74 at α = 0.05. PEG-priming outperformed the other priming and control treatments as it significantly produced more leaves, longer roots and shoots, and greater fresh and dry weights at α = 0.05. ABA-primed and GA-primed setups were outperformed by the unprimed setups in some parameters which can be attributed to suboptimal treatment concentration and duration. Notably, significant interaction effects between priming and cultivar were observed, indicating that priming effects may be less pronounced in tolerant cultivars due to their inherent salinity tolerance mechanism. Nonetheless, priming showed improved performance in susceptible and moderately tolerant cultivars, suggesting its ameliorative potential on the growth characteristics of rice under saline conditions.