Effect of Salinity on Germination and Seedling Growth of Four Medicinal Plants

This experiment was conducted in germinator in order to study the effects of water potential on seed germination, rate of germination and seedlings growth of four medicinal plants (Coriandrum sativum L., Plantago psyllium L., Descurainia sophia (L.) Webb ex Prantl and Portulaca oleracea L. Four water potential including distilled water as control (0), -0.37, -0.59 and -0.81 Mpa which made by different salts (NaCl, CaCl₂ and NaCl+CaCl₂ in 5 to 1 molar ratio). The experiment was carried out based on completly randomized design with six replications. Results showed that the effects of water potential, type of salt on germination percentage, rate of germination, root and shoot length were significant. With decreasing water potential, germination percentage and rate of germination declined but the response of plant were differ. Germination of Portulaca oleracea was not affected by decreasing water potential whereas others significantly decreased. The effect of salt composition was significant on rate and percentage germination. The percentage of germination at lower water potential (-0.37 MPa) which made by NaCl + CaCl₂ significantly was higher than the same water potential made by only NaCl and CaCl₂. Although, percentage and rate germination of Portulaca oleracea were not affected by different water potential, seedling growth of Portulaca oleracea significantly decreased.

Acknowledgement: I would like to express my appreciation for research deputy of the Ferdowsi University of Mashhad for financial support.