EFFECT OF PLANT GROWTH REGULATORS ON In vitro REGENERATION OF FOUR BANGLADESHI TOMATO (Solanum lycopersicum L.) VARIETIES

The study was conducted to determine the effect of plant growth regulators (PGRs) on in vitro regeneration of four Bangladeshi tomato varieties. Three explants (cotyledon, hypocotyl, and leaf segments) of four tomato varieties named-BT-2 (BARI Tomato-2), BH-T4 (BARI Hybrid Tomato-4), Apple tomato, and Native tomato were used for efficient regeneration through callus induction. MS medium fortified with varying concentrations and combinations of PGRs were employed for callus induction and subsequent plantlet generation. The nature and texture of callus were dissimilar based on varieties, types of explants, and hormonal combinations. The finest callus induction was recorded in MS+1.0 mg/L BAP + 1.0 mg/L NAA for leaf segment and cotyledon derived explants of BH-T4 and Apple tomato variety. The maximum shoot regeneration was obtained in 1.0 mg/L BAP+0.5 mg/L NAA and the highest root induction in 0.5 mg/L NAA+1.0 mg/L IAA hormonal combinations. Well rooted regenerated plantlets were acclimatized gradually and the best survival rate after acclimatization was 70%. Among the four varieties, BH-T4 and apple tomato variety were found to be the most responsive genotypes in terms of different parameters such as the capability to primary culture establishment, rate of callus induction, shoot initiation, and multiplication, root formation, and acclimatization. This investigation will helpful to produce a mass number of tomato plantlets each year.