In Vitro Method of High-Frequency Plant Regeneration Through Internodal Callus of Ruta graveolens L.

Abstract

Ruta graveolens L. is of considerable interest worldwide because of its medicinal properties. In vitro culture is a useful tool for both multiplication and study of important secondary metabolites. It was intended to develop an effective in vitro indirect propagation protocol for Ruta graveolens L. from internodal explants. The explants excised from 10-week-old plants were placed on Murashige and Skoog (MS) medium supplemented with various concentrations and combinations of auxins, indole-3-butyric acid (IBA), 2,4-dichlorophenoxy acetic acid (2,4-D), and naphthalene acetic acid (NAA), and cytokinins (benzyl amino purine (BAP) and kinetin) singly and in combinations for callus induction. The callus response was maximum (90.00 ± 1.66) in 2,4-D (1.5 mg/l) + NAA (1.5 mg/l). The friable callus obtained was subcultured on MS full-strength medium fortified with different concentrations of plant growth regulators. The highest percent response (81.22 ± 0.57) per culture for shoot bud regeneration was noted for the concentration of BAP (1.5 mg/l) with IBA (1.0 mg/l). The same concentration effectively increased the number of shoots per culture. Different concentrations of indole-3-butyric acid (IBA) and indole acetic acid (IAA) were used in half-strength MS medium for in vitro rooting of regenerated shoots. The maximum percentage of rooting (86.10 ± 0.50) and the highest number of root formations (8.11 ± 0.19) per shoot were observed on the medium containing 0.50 mg/l of IBA. Plantlets with well-developed root and shoot systems were successfully acclimatized (85%) and established in earthen pots.