Effect of moderate salinity on Golden Thistle (Scolymus hispanicus L.) grown in a soilless cropping system

Abstract

• Soilless cultivation of S. hispanicus l. improved plant growth and yield characteristics. • S. hispanicus L. was resilient to moderate salinity until 90 days after transplant. • Salinity level of 10.0 and 15.0 mM improved functional quality characteristics. • Physiological indicators significantly declined at salinity levels of 10 and 15 mM NaCl. Selecting salt-tolerant crop species for cultivation might be a feasible option to maintain crop productivity in arable lands affected by salinity. In this context, here we examine the responses of the wild edible green golden thistle ( Scolymus hispanicus L.) to moderate levels of salinity when grown in a soilless system for culinary use. Treatments were obtained by establishing four NaCl concentrations (0.5, 5.0, 10.0, and 15.0 mM) in a standard nutrient solution, resulting in initial solution electrical conductivities (EC) of 2.2, 2.8, 3.2, and 3.8 dS m − 1 , respectively. By the end of the experiment, 120 days after transplanting (DAT) drainage EC reached 2.65, 3.33, 3.96, and 4.51 dS m − 1 , respectively. At the first harvest, 90 DAT, the increase of the NaCl concentration had no significant impact on the number of leaves per plant, leaf fresh and dry weight [g plant −1 ], and root dry weight [g plant −1 ]. At the second harvest (120 DAT), 15.0 mM NaCl significantly decreased root and leaf fresh and dry weight without affecting the number of leaves per plant compared to 0.5 and 5.0 mM NaCl, while 10 mM NaCl had no impact on any of these parameters. The concentrations of K + , Ca 2+ , Mg 2+ , and P in the leaves were not influenced by the tested salinity levels, while those of organic-N and NO 3 − -N were significantly reduced by 10 and 15 mM NaCl, 90 DAT. Furthermore, 10 and 15 mM NaCl significantly increased the Cl − and Na + concentrations in leaves, but not in the roots. In the root tissues, only the K concentration was reduced by salinity while P increased at the highest salinity level (15 mM NaCl). Based on these results, we conclude that S. hispanicus L. is resilient to moderate salinity levels and can be considered a promising candidate plant for introduction to soilless cropping systems.