Comparative analysis of lily responses to elevated salinity in irrigation water: Effects on physiology, anatomy, and postharvest flower quality

Saline water irrigation presents a significant challenge in agriculture, especially in regions with water scarcity and soil salinity. Lilies are economically significant ornamental plants renowned for their aesthetic value and commercial importance. This study aims to evaluate the effects of saline water irrigation on lily anatomy, physiology, and postharvest flower quality. Three NaCl salinity levels with varying electrical conductivities (EC) (control 0.65, 3, and 6 dS m-1) were applied to three hybrid lilies (Lilium × elegans): fragrant Orienpet (‘Maytime’, white), non-fragrant Longiflorum-Asiatic (‘Pavia’, yellow), and ‘Fangio’ (pink). Overall, moderate salinity (3 dS m-1) significantly altered lily anatomy and physiology, resulting in reduced postharvest quality, particularly evident in leaf greenness, flower size, quantity, and vase life. Exposure of plants to higher salinity levels (6 dS m-1) resulted in significant reductions in leaf area (40%), plant height (21%), stem diameter (15%), chlorophyll content (29%), and photosynthesis (Pn) (20%) compared to the control. Analysis revealed thinner epidermal cell and parenchyma tissues, along with decreased ground tissue thickness, contributing to reduced stem diameter. Reduced photosynthesis in salt-stressed lilies was attributed to significant declines in stomatal conductance (gs) (72-80%) and abaxial stomatal index (69%). High salinity levels also led to decreased flower diameter, size, number of flowers per stem, and vase life. However, irrigation with saline water at 6 dS m-1 enhanced certain color attributes, including petal redness (a*) in ‘Fangio’ and yellow hue (b*) in both ‘Fangio’ and ‘Pavia’ hybrids, along with increased colorfulness/saturation levels (C*) across all cultivars. In conclusion, this study offers valuable insights into identifying anatomical stress indicators that elucidate physiological responses. These findings could contribute significantly to the development of effective stress mitigation strategies for lily cultivation, particularly in water-scarce and saline environments.