ADVENTITIOUS SHOOT REGENERATION FROM ROOT, INTERNODE, PETIOLE AND LEAF EXPLANTS OF PIPER COLUBRINUM LINK

A single-step, high-frequency regeneration protocol has been standardi sed for Phytophthora-resistant wild pepper, Piper colubrinum (Link) us ing root, internode, leaf and petiole explants derived from in vitro p lantlets. The effect of BA on shoot-bud induction and elongation was a ssessed by supplementing half-strength MS medium (macronutrients at ha lf 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 wa s studied by culturing the explants for 8, 15 and 30 days before the f irst 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 wildtyp e Piper colubrinum and the cultivated species P. nigrum.