Sudabeh Mafakheri. - Assistance professor, Department of Engineering and Technology, Imam Khomeini International University, Qazvin.Iran. Tel: +۹۸۸۳۷۱۲۱۸
Behvar Asgari. - Assistance professor, Department of Engineering and Technology, Imam Khomeini International University, Qazvin.Iran. Tel: +۹۸۸۳۷۱۲۱۸

The effect of salinity and gibberellic acid on seed germination and early embryo growth (radicle and shoot growth) of 5 medicinalplants was investigated in laboratory conditions. To this aim, various aqueous solutions of NaCl (0.1, 1 and 1.5 mol/l NaCl) and GA3 (100,200and 300 ppm) were used solely or combined as germination and growth substances. Two of the aqueous solution of NaCl (1 and 1.5 mol/l)negatively affected seed germination of all 5 plant species even when combined with GA3. Every 5 species seeds were germinated in presenceof 0.1 mol/l NaCl aqueous solution solely or combined with GA3. The results show that this treatment significantly decreased the germinationfactors in dill, peppermint, coriander and thyme but it increased germination percentage and germination rate in dragonhead. NaCl aqueoussolution significantly decreased the shoot and radicle length in 5 studied medicinal plants. GA3 significantly increased the shoot and radiclelength as well as the germination percentage and germination rate in the medicinal plants. Accordingly, germination and seedling growth of the5 medicinal plants species, responded differently to levels of NaCl and GA3

Gibberellic acid, NaCl, Seed germination, Seedling growth