Abstract

Lim D. Yoong, Karpal Tan Kwame and Loganathan Chaw

We present a successful regeneration of Orthosiphon stamineus plant from petiole. All of the explants were cultured on Murashige and Skoog (MS)-based medium supplemented with various concentrations of benzylaminopurine (BAP) and naphthalene acetic acid (NAA) at the growth condition (25 ± 2°C, 16-h photoperiod at light intensity of 22.85 µmol /m2 /s) for 8 weeks. Results showed that petiole explants cultured at combination of 1.0 mg/L BAP and 0.2 mg/L NAA gave highest number of shoot produced per explants (4.33 ± 0.33) and a maximum callus fresh weight gains (3.2 ± 1.9 g) as compared to other treatments. The first shoot was observed from petiole cultured at all treatments in 4 weeks culture except for 0.1 mg/L BAP + 0.5 mg/L NAA treatment. For root induction, treatment at 0.1 mg/L NAA produced the highest number of roots produced per shoot (9.8 ± 3.1) compared to other treatments. Regeneration comparison between petiole, young leaf and stem segments showed that petiole is the most suitable explant for an efficient plant regeneration system of O. stamineus.