An analysis of the effect of salinity on the germination and primary growth of five medicinal species (Hypericum perforatum, Foeniculum vulgare, Cuminum cyminum, Anthemis persica and Achillea millefolium)

For investigating the effects of salinity on the germination and growth of five medicinal species, an experiment carried out in 2010. Five medicinal species including Hypericum perforatum, Foeniculum vulgare, Cuminum cyminum, Anthemis persica and Achillea millefolium were analyzed at four levels of salinity (0, 50, 100 and 150 mM of sodium chloride in Petri dish) using a completely randomized, factorial design with four replications. The traits under analysis included the percentages and rate of germination, the length of root and shoot, the length of seedling, S/R (shoot/root), the fresh and dry weights of the seedling, and the vigor index. The statistical analyses at germination and seedling growth levels indicated that an increase in salinity significantly decreased all of the traits at P<0.01 and S/R at P<0.05 in the five species under analysis. The highest percentage and rate of germination belonged to Anthemis persica and Achillea millefolium, and the lowest effect of salinity on the percentage and speed of germination was observed in 50 mM and control concentrations. The obtained results regarding the length of root, shoot, and seedling indicated that this decrease was more in 50 and 150 mM concentrations in comparison to 100 mM one. It must be noted that the 100 mM salinity level had the lowest amount of S/R.