Thidiazuron-induced high frequency of shoot induction and plant regeneration in protoplast derived pea callus

Abstract
Protoplasts isolated from lateral shoot buds of cotyledon-free pea embryo axes were regenerated to callus. Protoplast derived calluses with a diameter of about 1cm were transferred to shoot induction media, containing different concentrations (1–50µM) of thidiazuron. Shoot formation was observed after 16 weeks up to 12% efficiency. Thidiazuron (10µM) was the most effective concentration in all experiments. Shoot buds elongated in medium supplemented with N-isopentenyl adenine and indole-3-butyric acid. Since rooting was almost impossible in these thidiazuron-induced shoots, shoots were grafted onto young pea seedlings and regenerated to fertile plants.