After approximately one week, most explants turned green and the node began to expand. Visible elongation of the node on shoot induction medium was observed within 10 days. New budding gradually occurred and reached climax at 3 to 4 weeks (Fig. 1 a–d). Basic culture medium had a significant impact on shoot initiation. For all tested cultivars the proliferation frequency was higher and shoots grew more vigorously on MS medium than on WPM, on which stem browning occurred and growth was slower.