Effects of Salinity and Water Stress on Seeds Germination of Origanum majorana cultivated in Morocco

This study investigates the effect of salt and water stress on the germination performance of Origanum majorana seeds. Salinity was applied using 0, 50, 100, and 150 mM NaCl, while water stress was simulated, using PEG 6000, at values of 0, -0.1, -0.7, and -1 MPa. In all treatments, germination percentage and rate of germination were measured. Results showed that germination decreased with increasing salt and water stress. However, at 50 mM NaCl (moderate salinity) or -0.1 MPa (moderate water stress), germination remained high (about 82-85%) and comparable to the control. High salinity (>100 mM NaCl) or intense water stress (-0.7 MPa and above) reduced germination to below 40-45%. Germination curves exhibited a typical sigmoid shape due to their longer lag times and lower germination rates under salt and water conditions. The results obtained suggest that Origanum majorana shows moderate tolerance to salinity and is highly sensitive to intense environmental stress. Hence, the current experiment indicates that Origanum majorana is moderately tolerant to salt stress and highly sensitive to stronger stress conditions, confirming that appropriate management is needed if this plant is cultivated in arid and semi-arid conditions.