Clonal propagation of Rudraksha (Elaeocarpus angustifolius Blume) using DKW medium and validation through molecular markers

Elaeocarpus angustifolius Blume (Elaeocarpaceae), commonly known as Rudraksha, is a tree of significant religious and medicinal value in India, with approximately 29 species. Due to poor seed germination rates, developing an efficient in vitro propagation method is crucial for providing horticulturists with high-quality planting material. In this study, a micropropagation protocol was successfully standardized for E. angustifolius using nodal explants in Driver-Kuniyaki-Walnut (DKW) medium. The DKW medium supplemented with 2 mgL⁻¹ kinetin yielded the highest shoot proliferation, with an average of 27.6 ± 0.7 shoots per explant and an average shoot length of 3.1 ± 0.3 cm. Furthermore, a half-strength DKW medium, in combination with indole-3-butyric acid (IBA), achieved a 95% rooting frequency. Optimal rooting was observed with 2.5 mgL⁻¹ IBA, resulting in an average of 5.4 ± 0.2 roots per shoot, and an average root length of 4.4 ± 0.2 cm. The in vitro–derived plantlets were successfully acclimatized in sterilized vermiculite before being transferred to field conditions, where they exhibited a 100% survival rate. The clonal fidelity of these plantlets was confirmed using RAPD, ISSR, and SSR markers revealing 28 bands in RAPD, 36 bands in ISSR, and 6 bands in SSR, all indicating monomorphism and confirming genetic uniformity with the mother plant. This optimized protocol supports the mass propagation of genetically uniform E. angustifolius, facilitating their widespread cultivation for both therapeutic and religious purposes.