2025/01/21 by Yousefi, Borzou, Karamian, Roya
#Chlorophyll index #Maximum quantum yield of photosystem II #Photosynthesis #Proline #Salt stress
paper · doi:10.57647/j.jrs.2025.1501.04
Satureja mutica Fisch. & C. A. Mey is a wild and perennial species which grows in the northwestern, north, and northeastern of Iran, and it is used in health industries and food products. In order to investigating the moderating effect of Salicylic Acid (SA) on morpho-physiological traits of the S. mutica under salinity stress conditions, a pot experiment was performed as a factorial experiment based on a Completely Randomized Design (CRD) and three replications at the Kermanshah Agricultural & Natural Resources Research & Education Center, Iran, in 2019. Factor A was NaCl in four levels (0, 50, 100, and 150 mM) and Factor B was salicylic acid at two levels (0 and 2 mM). The results obtained from the analysis of variance showed a significant difference in the studied traits. The salinity stress reduced plant height, leaf area, leaf fresh and dry weight, root fresh and dry weight, shoot fresh and dry weight, relative water content, chlorophyll index, and maximum quantum yield of Photosystem II (PSII)(Fv/Fm value), but increased leaf Electrical Conductivity (EC), and proline content. Soluble protein increased at 50 and 100 mM NaCl, but it significantly decreased at 150 mM NaCl. Salicylic acid caused an increase in plant height (17.54%), leaf area (24.62%), leaf fresh weight (12.41%), leaf dry weight (8.23%), shoot fresh weight (25.87%), shoot dry weight (13.75%), root fresh weight (70.99%), root dry weight (72.38%), relative water content (32.85%), maximum quantum yield of PSII (Fv/Fm value) (10.42%), and chlorophyll index (11.36%) compared to non-SA-treated plants. SA reduced proline content (12.07%) and leaf electrical conductivity (2.37%) in the SA-treated plants compared to non-SA-treated plants. The tolerance threshold for salinity of S. mutica was less than 100 mm and in salty soils more than this value, its growth and yield significantly decreases. Foliar spraying with 2 mM salicylic acid in S. mutica plants exposed to salt stress, in the early stages of vegetative growth, enhanced the plant's tolerance to salinity and increased plant yield.