Development of an efficient In vitro Regeneration protocol in tomato (Solanum lycopersicum L.)

A protocol was developed for in vitro regeneration through somatic embryogenesis and organogenesis in tomato genotypes Roma, Punjab Ratta and Castle Rock. Hypocotyl and leaf explants were cultured on MS medium having different concentrations of hormones for callus induction. Maximum callogenesis from both hypocotyl and leaf explants was obtained on MS medium supplemented with 2, 4-D (2 mg/l) and Kin (0.5 mg/l). It was 86.66% for leaves and 70% for hypocotyls. Calli were cultured on MS medium having different concentrations of BAP (2–2.5 mg/l) and NAA (0.25–0.5 mg/l) for regeneration. But calli did not show any response for further callus growth and plant regeneration. However, in direct plant regeneration through organogenesis, shoot tip and hypocotyl explants were cultured on MS medium supplemented with Zeatin (1 mg/l) + IAA (0.1 mg/l) and BAP (2 mg/l) + NAA (0.2 mg/l). The maximum direct plant regeneration was obtained from both shoot tip and hypocotyl explants of genotype Punjab Ratta on MS medium supplemented with zeatin (1 mg/l) + IAA (0.1 mg/l). It was 81.66% for shoot tips and 73.33% for hypocotyls. Rooting was observed at half MS and 0.1 mg/l IBA. Rooted plantlets were made to acclimatize, hardened and gradually transferred to the pots.