Salinity effect 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، germination rate and seedlings growth of four medicinal plants as Trigonella foeaum-graecum L.، Sesamum indicum L.، Cannabis sativa L. and Carum copticum (L.) C. B. Clarke. Four water potential were used including distilled water as control (0)، -0. 37، -0. 59 and -0. 81 Mpa which has been made by different salts (NaCl، CaCl2 and NaCl+CaCl2 in 5 to 1 molar ratio). The experiment was carried out based on completely randomized design with six replications. Results of variance analysis showed that effects of water potential، type of salt composition on germination percentage، rate of germination، root and shoot length were significant. With decreasing water potential، germination rate and percentage decreased. Of cource plants had different responses such as Sesamum indicum was not affected by decreasing water potential where as other significantly were decreased. The effect of salt composition was significant on rate and percentage of germination. The percentage of germination at lower water potential which was made by NaCl+CaCl2 significantly was higher than the same water potential made by only NaCl and CaCl2.