Adventitious shoot regeneration from root, internode, petiole and leaf explants of Piper colubrinum Link.

A single-step, high-frequency regeneration protocol has been standardised for Phytophthora-resistant wild pepper, Piper colubrinum (Link) using root, internode, leaf and petiole explants derived from in vitro plantlets. The effect of BA on shoot-bud induction and elongation was assessed by supplementing half-strength MS medium (macronutrients at half the concentration) with different concentrations of BA, i.e. 0.2-10 mg l(-1) in induction media and 0, 0.2 and 0.5 mg l(-1) in subculture media. The interaction between culture period and BA concentration was studied by culturing the explants for 8, 15 and 30 days before the first subculture. The elongated shoots were rooted directly in soil and hardened in the greenhouse. The developed protocol would be useful in marker-assisted asymmetric hybridisation programmes involving wildtype Piper colubrinum and the cultivated species P. nigrum.