Soil salinity, which used to raise less concern in the past, and is perceived as an important threat to the future of plant production in many parts of the world today, is one of the most important abiotic stress factors that inhibit plant growth and crop productivity. Plants are exposed to salt stress in a large part of the earth's soil, especially in arid and semi-arid lands. In addition to intensive efforts to improve the physicochemical properties of saline soils by applying different reclamation procedures, a high number of studies have been carried out in order to determine the variation in the salt tolerance of cultivated plants in particular. The majority of these studies are at genotype level. By using different types of salt of Na+ cation origin in the two different genotypes of Raphanus sativus L. (turnip) plant, which is known to have low salt tolerance, our study attempts to find the answer to the following question: ''Is it possible to perceive the positivity of cotyledon opening frequency as a stress parameter in structural properties affected by salt in very young seedlings that develop following the germination in epigeal germinating seeds?'' The conclusion reached was that the positivity of cotyledon opening frequency can be perceived as a stress parameter in the evaluation of the responses of certain plant genotypes to salt stress depending on the salt type and amount and incubation conditions in epigeal germinating seeds.