CALLUS INDUCTION AND PLANTLET REGENERATION FROM SHOOT TIP EXPLANTS IN TOMATO (Solanum lycopersicum L.)
The experiment was conducted on in vitro regeneration of tomato at the Plant Biotechnology Laboratory from May 2013 to April 2014, Department of Horticulture, Patuakhali Science and Technology University, Patuakhali. The objective was to develop an efficient regeneration protocol in tomato through callus induction for subsequent plantlet regeneration from shoot tip explants. Seeds were inoculated on MS medium where germination rate was 78.4%. The shoot tips of in vitrocultured seedlings were used as explants. Different concentration and combination of growth regulators were added to MS medium to observe their efficacy on callus induction, shoot initiation and root formation. Shoot tip explants cultured on MS medium fortified with 2 mg/L BAPgave the highest number of shoots (3.25) at 45 DAC. Among the concentrations of PGRs, 0.25 mg/L IAA produced the highest length (4.685 cm) of plantlets, number(5.25) of leaves and fresh weight (0.7130 g) of plantlets with the shoot tips explants at 45 DAC. The concentration of 0.5 mg/L IAA produced the highest number (23.50) of roots/plantlet, length (8.004 cm) of roots at 45 DAC, from the same explants. The highest survival rate of in vitro regenerated plantlets in the pot was 70.00 % with the shoot tips explants.