In vitro seed germination of some Algerian medicinal plants and the effect of Gibberellic acid (GA3) on breaking dormancy

In the present study,we investigated the seed germination behaviour of three medicinal plants growing wild in algeria: thymus algeriensis boiss & reut.,rosmarinus officinalis l.,marrubium vulgare l. and assessed the effect of gibberellic acid (ga3) on breaking seed dormancy. the seeds were sterilized in 5% sodium hypochlorite solution (naocl) and subjected to two experiments. first,an examination of the seed germination ability without pre-treatment by incubating the seeds at ambient temperature (23±2 °c) and continuous darkness. secondly,the seeds were treated with various doses of ga3 (125,250,500 mg/l) and incubated in thermoperiod (25°c/16h,15°c/8h) and continuous darkness. from the experiment one,t. algeriensis seeds presented the highest germination percentage (94.43 %) followed by m. vulgare (57.76 %). however,r. officinalis seeds did not germinate. the ga3 treatment did not exhibit any significant effect (p > 0.05) on the germination of the three tested plants. in addition,the highest germination rates were observed in t. algeriensis seeds (80 and 100 %) and m. vulgare (53.3,73.3 and 86.7 %). r. officinalis seeds presented very low germination rates with (3.3,6.7 and 16.7 %). © 2017,university of mohammed premier oujda morocco.