Effect of growth regulators on in vitro germination of Artemisia absinthium

The present study was carried out to optimize the plant growth regulator conditions of callus formation, shoot regeneration and root induction, by using various explants of Artemisia absinthium. Leaf, hypocotyl and root explants of 1 to 3 weeks old in vitro grown seedlings were used for callogenesis and direct organogenesis at different concentrations and combinations of phytohormone added in B5 medium. The best callus formation and shoot regeneration response was observed from leaf explants obtained from 1 week old in vitro grown seedlings of A. absinthium. The leaf explants produced the best callus cultures when grown on B5 medium and contains either 0.1 mg/L benzyl aminopurine (BAP) or 0.1 mg/L kinetin (Kin) while root explants produced the best callus culture when placed on B5 medium containing 0.5 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) or 1 mg/L naphthaleneacetic acid (NAA). Callus cultures obtained from leaf explants when placed on 0.1 mg/L BAP were green and more compact led to shoot formation. Direct shoot regeneration response of leaf explants was the best when placed on B5 medium with either 0.1 mg/L BAP or 0.1 mg/L Kin. The produced healthy shoot induced the good roots when placed on B5 medium containing 0.025 mg/L NAA and 0.1 mg/L BAP.   Key words: Artemisia absinthium, plant growth regulators, callogenesis, organogenesis, Gamborg’s B5 medium.