Morphogenetic potential of foliar explants in Duboisia myoporoides R.Br. (Solanaceae)

The effects of serial combinations of either indole-3-acetic acid, indole-3-butyric acid or α-naphthaleneacetic acid (0.5-10.0 mg/l) with either kinetin, 6-benzyl-amino-purine, zeatin or 6-methylaminopurine (0.5-5.0 mg/l) have been investigated to assess the morphogenetic potential of foliar explants of Duboisia myoporoides. Shoot buds developed either directly or via a callus interphase. Combinations involving indole-3-acetic acid with any of the cytokinins were more effective in inducing shoot bud formation compared to those containing indole-3-butyric acid or α-napthalenacetic acid as an auxin. Among cytokinins, zeatin, kinetin and 6-benzylamino-purine were equally effective for shoot formation. However, optimum response with zeatin could be achieved at low concentrations (0.5-2.0 mg/l), while kinetin and 6-benzylamino-purine exhibited comparable efficacy at higher levels (3.0-5.0 mg/l). 6-Methylaminopurine proved least effective in all concentrations and combinations tested. Rooting of the differentiated shoots was readily achieved with α-naphthaleneacetic acid alone (0.5 mg/l) after changing the physical form of the medium from gel to static liquid. Regenerated plantlets were transferred to pots and grown to maturity in the field with a high rate of survival (80-90%).