Thidiazuron Enhanced Shoot Regeneration from different Varieties of Tomato (Lycopersicon esculentum Mill.)

The shoot regeneration capacity of three varieties of tomato viz., Pusa Ruby, Pusa Early Dwarf, and S-22 from two explants (cotyledons and hypocotyls) were tested on MS medium containing different concentrations of BAP, Kn, TDZ, 2-ip, and zeatin either individually or in combination with IAA. Shoot differentiation potential of the three varieties varied depending on the type of plant growth regulator, variety, explant type and age of explant. Highest shoot organogenesis frequency was recorded in hypocotyl explants from the variety Pusa Ruby followed by S-22. The growth regulator, thidiazuron enhanced the shoot differentiation frequency irrespective of the variety when compared with others. Explants isolated from 12-day-old seedlings were found ideal for higher frequency of regeneration compared to younger or older seedlings. Regenerated shoots were rooted on MS medium containing 1.0 mg/l NAA and the whole plants were transferred to pots with 75-80% survival.