Abstract
The current study was conducted to investigate the influence of salinity stress, salicylic acids (SA) treatments and their combinations on growth, yield , volatile oil content and some physiological and biochemical characters of (Rosmarinus officinalis L. ) plant. Salinity levels were 0, 25, 50 and 100 mM NaCl and SA concentrations were 0, 0.2 and 0.4 mM. Salinity treatments significantly decreased fresh and dry weights of herb, relative water content (RWC) compared with the control. The volatile oil percentage was increased with increasing salinity; however the volatile oil yield was not significantly affected. The chlorophyll content was reduced unlike membrane permeability, malondialdehyde (MDA) and proline content which increased as a result of applying salinity. The percentages of N, P, K, and Mg were reduced with increasing salinity concentrations. Meanwhile, Na and Cl were gradually increased with increasing salinity levels. The foliar application of SA alleviated the abovementioned negative effects of salinity on growth, herb and volatile oil yield and the physiological and biochemical characters investigated. The contents of RNA and DNA as well as RNA/DNA ratio were significantly decreased due to salinity application. However, SA treatment increased those parameters relative to the control. The increment of RNA and DNA as well as proline accumulation as a result of SA treatment are suggested to involve as a part of the defense against salinity in rosemary plant.