1- Sari University of Agricultural Sciences and Natural Resources
2- Sari University of Agricultural Sciences and Natural Resources , somaye.tayefeh1388@gmail.com
Abstract: (48 Views)
Objective: This study aimed to investigate the effects of salicylic acid (SA) responses of ornamental kale (Brassica oleracea var. acephala) under salinity stress.
Research Background: Previous studies have demonstrated that salicylic acid, as a plant growth regulator, effectively mitigates the detrimental effects of abiotic stresses including salinity in various plants; however, limited information is available regarding its impact on ornamental plants, particularly ornamental kale.
Methods: This study was conducted as a factorial design in a completely randomized block with three replications in a greenhouse at Sari Agricultural Sciences and Natural Resources University. Two factors were evaluated: salicylic acid concentrations (0, 100, and 200 mgL-1) and salinity levels (0, 2.5, and 5.12 dSm-1). Fifty-four ornamental kale seedlings at the four-leaf stage were planted in 27 pots containing a mix of loamy soil, perlite, and coco peat. Salicylic acid was applied via foliar spraying five times (every three days) over two weeks, followed by salinity stress induced using sodium chloride solution over two weeks. Plants were nourished with Hoagland’s solution. Measured traits included morphological characteristics, physiological parameters and phytochemical properties assessed using standard protocols.
Results: The results showed that Salinity alone negatively affected growth traits, particularly reducing leaf number. However, salicylic acid significantly mitigated these adverse effects. At 2.5 dSm-1salinity, 200 mg/L salicylic acid increased chlorophyll a by 195% and chlorophyll b by 65% compared to the control. At 5.12 dSm-1salinity, 100 mgL-1 salicylic acid improved leaf turgor weight by 20% and significantly enhanced antioxidant capacity. Total phenol and flavonoid contents also increased significantly.
Conclusion:Salicylic acid enhances moderate salinity tolerance in ornamental kale by improving photosynthesis, maintaining water balance, and increasing antioxidant compounds. Concentrations of 100 and 200 mgL-1 were most effective at 2.5 dSm-1salinity. Application of this growth stimulant is recommended for developing sustainable green spaces in moderately saline areas.