The Effect of NaCl Stress on Biochemical, Physiological, Photosynthetic and Morpho-physiological Indicators of the Medicinal Plant Forest Savory

Satureja mutica Fisch. & C. A. Mey (Forest Savory) is a valuable wild plant species widely used in the medicinal, health, and food industries. In this study, we investigated the effects of ۰, ۵۰, ۱۰۰, and ۱۵۰ mM NaCl on various physio-biochemical, morpho-physiological, and photosynthetic parameters of this plant through a greenhouse experiment. The experiment was conducted using a randomized complete block design (RCBD, r = ۳) at the Agricultural and Natural Resources Research Center, Kermanshah, Iran. The highest shoot fresh weight (۱۷.۸۰ g) and shoot dry weight (۶.۷۳ g) were observed in the control plants. The highest essential oil content (EO) percentage (۳.۵۱%) was recorded in plants treated with ۱۰۰ mM NaCl. The results showed that NaCl concentrations of ۱۰۰ and ۱۵۰ mM significantly reduced the leaf dry weight (by ۳۷.۱۳% and ۴۱.۸۶%), the shoot dry weight (by ۵۱.۵۴% and ۸۲.۷۴%), root fresh weight (by ۷۷.۹۲% and ۸۲.۷۴%), and the root dry weight (by ۷۰.۷۹% and ۷۸.۹۷%). Additionally, ۱۰۰ and ۱۵۰ mM NaCl significantly decreased leaf areas (by ۲۳.۵۵% and ۲۸.۰۱%), leaf relative water content (by ۲۵.۶۶% and ۲۸.۵۳%), SPAD values (by ۶.۳۶% and ۴۱.۳۵%), and the Fv/Fm ratio (by ۱۰.۲۱% and ۱۶.۴۰%). Furthermore, ۱۵۰ mM NaCl resulted in a ۴۴.۸۱% reduction in the photosynthetic index (PI). The ۵۰ and ۱۰۰ mM NaCl treatments significantly increased leaf protein content by ۵۰.۶۷% and ۸۲.۲۲%, respectively, whereas ۱۵۰ mM NaCl significantly decreased it. All salinity treatments caused a sharp increase in leaf proline content. In conclusion, the results confirmed that S. mutica is sensitive to salinity concentrations of ۱۰۰ mM and higher, and thus, cultivating this plant in semi-saline or saline soils is not recommended.

کلیدواژه ها:

Forest savory ، Medicinal plants ، Photosynthesis ، Salt stress