1Laboratoire de Chimie Organique Appliquée, département de chimie, Faculté des Sciences Semlalia, Université Cadi Ayyad, Marrakech, Morocco.
2Laboratoire de Biotechnologies, Protection et Valorisation des Ressources Végétales, département de biologie, Faculté des Sciences Semlalia, Université Cadi Ayyad, Marrakech, Morocco.
An experiment was conducted to assess the effect of salt stress on germination, plant growth and aerial part essential oil content in an endemic medicinal plant in Morocco (Thymus broussonetii Boiss.). Five NaCl concentrations (0, 50, 100, 150, 200 mM) performed in the dark at 15°C, 20°C and 25°C were used at germination and four NaCl concentrations (0, 25, 50, 100 mM) were used at plant growth. For the two stages, we assessed germination percentage, fresh and dry weight of plant shoots, roots, green aerial part (leaves and inflorescences) and aerial part essential oil content. Increasing salinity lowered the germination and reduced the final germination. The temperature of incubation presented a significant effect on salt sensitivity of this species at the germination stage. The highest values of germination were observed at 20°C. At the seedling stage, increasing salt levels caused a significant reduction in fresh and dry masses of both shoots and roots. However, this reduction was more pronounced on root than on shoot. This study showed that the aerial part oil content of this species did not change with increase in external salt level. Overall, T. broussonetii did not behave to salinity as a halophyte but rather as moderately salt tolerant species.
salt tolerance, medicinal plant, domestication, sustainability
