Application of Ascophyllum nodosum-Based Soluble Extract on Micropropagation and Regeneration of Nicotiana benthamiana and Prunus domestica

In the present study, the effect of a commercial extract of the seaweed Ascophyllum nodosum on in vitro micropropagation, shoot regeneration, and rhizoghenesis were studied in Nicotiana benthamiana and Prunus domestica. Results showed that the MS medium supplemented with various concentrations of the Ascophyllum extract (5, 10, 50, and 100 mg L−1) significantly enhanced the number of regenerated buds from N. benthamiana leaf discs to the conventional MS regenerating medium. Increases ranged from 3.5 to 6.5 times higher than the control. The effect of the Ascophyllum extract on N. benthamiana micropropagation was assessed through the measurement of some plant growth parameters. Results showed that the extract alone could not replace the micropropagation medium since shoot length, shoot diameter, root length, and leaf area were significantly reduced. However, its combination with a half-strength MS medium enhanced these parameters. Its effect was also evaluated on regeneration from plum hypocotyl slices. When added to the shoot regeneration medium without any plant growth regulators, the Ascophyllum extract alone could induce shoot regeneration. However, the percentage of bud regeneration and number of regenerated buds were lower than with the conventional shoot regeneration medium containing complete growth regulators. In contrast, the Ascophyllum extract drastically promoted rhizogenesis from plum hypocotyl slices. These results pave the way for the possible use of A. nodosum extracts in in vitro mass propagation of higher plants.