Effect of Plant Growth Regulators (BA, KIN and NAA) on In vitro Propagation of Papaya (Carica papaya)

The present research was carried out in Biotechnology Laboratory of the Department of Biotechnology, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka-1207 from the period of September 2017 to June 2018. This research aims to study the effect of Benzyladenine (BA), Kinetin (KIN) and Naphthalene acetic acid (NAA) either in combination or alone on In vitro propagation of papaya (Carica papaya). The shoot tips of young shoots were used as explant, which was sterilized using freshly prepared 0.1% HgCl2 mixing with few drops of Tween-20, were inoculated in MS media supplemented with 0.1% activated charcoal. The minimum days to shoot induction (10.25) were recorded on MS medium containing 0.5 mg/L BA. The highest shoots (4.5) and length of shoot (5.75 cm) observed in 1.0 mg/L BA. The combined treatment 1.0 mg/L BA+0.75 mg/LKIN gave the highest number of shoots (5.25) and length of shoot (5.78 cm).The minimum days (8.5) to root induction was reported in 2.0 mg/L NAA along with maximum 8.25 roots per plantlet. The highest length of root (6.92 cm) was observed in 2.0 mg/L NAA. In regenerated plantlets, 80% survival rates were observed in growth chamber conditions and 75% in the open atmosphere were achieved. Finally, the in vitro regeneration protocol described herein can potentially be used as a tool in molecular breeding programs for the improvement of different cultivars and genotypes of papaya.