Silicon-Mediated Alleviation of Salinity Stress in Petunia (Petunia hybrida) by Modulation of Morphological, Physiological and Biochemical Indices

Purpose: Petunia is a well-known winter annual ornamental plant cultivating in Pakistan. The production and flower quality of petunia is very low due to abiotic stressors. Among these, salinity is drastically affecting the growth, yield, and vase life of petunia. The current aim was to determine the beneficial impact of silicon (Si) on petunia under sodium chloride (NaCl) stress. Methods: Saline concentrations (0, 30, 60, and 90 mM NaCl) with irrigated water were practiced on petunia. Moreover, Si levels (control, 40, 80, and 120 mg L^− 1) were also sprayed after two weeks of saline irrigations. Results: The stunted growth i.e., plant height, plant fresh and dried weights, number of branches, leaf size, number of leaves, leaves fresh and dried weights, root fresh and dried weights, and root length was documented at 90 mM NaCl. The maximum increase in growth traits and flower production was recorded under the supplementation of Si at 120 mg L^− 1. The maximum malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) were recorded during 90 mM NaCl, while Si spray at 120 mg L^− 1 reduced the MDA and H₂O₂ activities. Enzymatic and non-enzymatic activities were increased to scavenge toxic reactive oxygen species (ROS) by supplementation of Si (120 mg L^− 1) under salinity. Signaling molecules were reduced with Si spray under salinity. Si at 120 mg ^− 1 improved the photo-pigments under different salinity levels. Conclusion: So, current findings indicated that Si had the potential to cope with adversities that occur from salinity in petunia.