Improving an in vitro propagation protocol for Cestrum nocturnum L.
The present study was carried out to assess the micropropagation of <em>Cestrum </em>(<em>Cestrum nocturnum<strong> </strong></em>L.) by using single nodes and shoot tips excised from soft cuttings using MS salts, 30 g × l<sup>-1</sup> sucrose, 7 g × l<sup>-1</sup> agar, and different concentrations of plant growth regulators in culture medium.<strong> </strong>The results revealed that the use of mercuric chloride (0.05%, HgCl<sub>2</sub>) 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<sup>-1</sup> 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<sup>-1</sup>) with 0.2 mg × l<sup>-1</sup> 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<sup>-1</sup> 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<sup>-1</sup> 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.