Alleviation of salinity stress on Rosa hybrida L. cv. 'Dolce Vita by foliar application ‎of calcium carbonate nanoparticles ‎

To investigate the effect of foliar application of calcium carbonate nanoparticles (CCN) and indirectly increasing carbon dioxide concentration on salt stress modulation of rose 'Dolce Vita., a soilless culture experiment was conducted as a randomized complete blocks design with three replications, in which the pots were filled with a mixture of cocopeat and perlite. The first factor was salinity at two levels (1.8 and 3.2 dS m-1 by adding NaCl to the nutrient solution) and the second factor was foliar spraying of CCN at four levels (0, 3, 6 and 9 g L-1 by using Lithovit fertilizer). Increasing salinity and the concentration of CCN had no effect on potassium and sodium contents of leaves and electrolyte leakage of leaf cells. The salinity of 3.2 dS m-1 reduced the relative humidity of leaf and increased the dry matter percentage and soluble sugar content in the plant leaves; however, had no significant effect on studied morphological characteristics. The application of CCN significantly increased the relative humidity of leaves in both saline and non-saline treatments and the mean of morphological traits (leaf area, flower diameter, stem length and flower yield). In addition, the application of 6 and 9 g L-1 CCN significantly increased the concentration of chlorophyll, carotenoid, and leaf soluble sugar; however, salinity had no effect on these characteristics. Results showed that foliar application of CCN, by affecting physiological and morphological traits and improving plant nutrition, modulates salinity stress and improves the growth conditions of Dolce Vita rose.