Improving an in vitro propagation protocol for Cestrum nocturnum L.

The present study was carried out to assess the micropropagation of Cestrum (Cestrum nocturnum L.) by using single nodes and shoot tips excised from soft cuttings using MS salts, 30 g × l^-1 sucrose, 7 g × l^-1 agar, and different concentrations of plant growth regulators in culture medium. The results revealed that the use of mercuric chloride (0.05%, HgCl₂) for 7 minutes was very effective in preventing contamination and gave the highest survival percentage (99%). The highest response (100%) was gained at initiation stage from lateral bud explants on MS medium supplemented with 1.5 mg × l^-1 of BA with most of NAA concentrations. However, in case of terminal buds, higher percentages of responses were resulted from the interaction of BA (1.5 mg × l^-1) with 0.2 mg × l^-1 NAA. The lateral buds also produced more new shoots as well as a higher number of leaves and length of new shoots on the medium supplemented with 1.5 mg × l^-1 BA as compared with those from terminal buds. Significant differences were observed at multiplication stage between the lateral buds and terminal buds, since the lateral buds produced a higher number of new shoots and leaves as well as longer new shoots. At rooting stage, the treatment with 1 mg × l^-1 IBA gave the highest percentage of rooting (100%), the highest number of roots (13.2 root/explant), and the longest roots (8.44 cm), respectively, on half strength MS medium. Plantlets obtained were transferred to pots and acclimatized with 90% success