Study of in vitro-induced salinity on osmolytes accumulation and physiological and biochemical traits of Damask rose landraces

Salinity is one of the important environmental factors that reduces the growth and performance of plants, especially in arid and semi-arid regions of the world. Damask rose (Rosa damascena Mill.) is one of the most important medicinal and ornamental plants in the country. Considering that the expansion of plants tolerant to salinity stress is one of the important goals of breeding and production programs, in this case a factorial experiment in a completely randomized design with three replications was done during 2020–2021 in the laboratory of the Department of Science and Engineering, Faculty of Agriculture, University of Maragheh, under in vitro conditions on four Damask landraces including Atashi, Bikhar, Chaharfasl and Kashan at 5 salinity levels of 0, 25, 50, 75 and 100 mM NaCl and the physiological and biochemical traits of them were evaluated. The results showed that the physiological and biochemical characteristics of Damask landraces caused an increase in antioxidant enzyme activities and compatible osmolytes. The Atashi landrace with high photosynthetic pigments, relative water content, proline, total soluble protein and the highest increase in antioxidant enzymes activity and, on the other hand, the lowest amount of hydrogen peroxide and electrolyte leakage, was more tolerant to salinity compared to other landraces. Compared to other genotypes, the Atashi genotype was the most favorable and tolerant, with the highest optimal level of antioxidant activity and the accumulation of compatible osmolytes, as well as a high concentration of total soluble protein. The tolerance threshold of Atashi landrace to the in vitro-induced salinity was estimated at 75 mM NaCl.