Fatemeh Panahi - Assistant Professor, College of Natural Resoources and Earth Sciences, University of Kashan. Kashan. Esfahan. Iran
Mohammad Hassan Asareh - Professor, Research Institute of Forest and Rangeland. Tehran. Iran
Mohammad Jafari - Professor, College of Natural Resources, University of Tehran. Karaj. Iran
Alireza Givar - MSc of Law. PN University. Tehran. Iran

Objective: Salt stress is a world-wide problem and soil salinity is common in arid and semi-arid regions. This study was undertaken to investigate salt tolerance in Salsola orientalis in laboratory and natural conditions and recognize the mechanisms that allow it to tolerate these conditions. Methods: This study had two parts of greenhouse and natural habitats. The treatment solutions for salinity tests were different concentrationsof NaCl and Na2SO4 (0, 100, 200, 300, 400, and 500 mM) with three replicates andgrowth parameters and proline and soluble sugar were determined in vegetative growthstage in greenhouse. Soil (two depths of 0-10 cm and 10-45 cm) and plant (root and shoot) samples have been harvested from three 200 meters transects in three provinces of Esfahan, Semnan and Markazi. Plant proline and soluble sugar and soil texture and ECwere measured in laboratory. Collected data were analyzed using a factorial experiment and means were compared by DMRT method by SPSS software. Results: Resultsindicated that proline and soluble sugar were significantly affected by salinity levels and increased with salinity increase. The rate of growth parameters increased with an increase in salinity up to 300 mM while salinity levels more than 300 mM NaCl caused allgrowth characteristics decline. Data obtained from the laboratory experiment confirmed the findings noted during the field study. It has to be mentioned that nature is unpredictable and observing unexpected trends under specific conditions is not impossible.

NaCl ، Na2SO4 ، Salsola orientalis ، Salt tolerance ،