In vitro approaches for conservation and reducing juvenility of Zanthoxylum armatum DC: an endangered medicinal plant of Himalayan region

Key message This paper provides authentic information on the micropropagation and genetic fidelity assessment methods, which can be used for conservation and quality assessment of endangered medicinal plant Zanthoxylum armatum. Abstract An in vitro propagation protocol for Zanthoxylum armatum (local name—Timur, Family-Rutaceae), an endangered medicinal plant of the Himalayan region, has been developed through culture of nodal explants. Use of Murashige and Skoog (MS) medium, supplemented with 12.0 µM 6-benzylaminopurine (BAP), 0.5 µM indole-3-acetic acid (IAA), and 0.5 µM gibberellic acid (GA 3 ), resulted in good shoot proliferation (4.78 ± 0.18 shoots/explant) and shoot length (3.46 ± 0.05 cm). One hundred percent rooting was achieved through pulse treatment of shoots on full-strength MS medium supplemented with 50.0 µM indole-3-butyric acid (IBA) for 12 h, followed by subsequent transfer to half strength MS medium without plant growth regulators (PGRs). The plant survival was found to be 75% following acclimation. Plants started to flower after 1 year of transfer to soil under nursery conditions. Genetic stability of the regenerated plants was assessed using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers. Results confirmed monomorphic nature of regenerated plants, matching with that of the mother plant, and thus genetic fidelity of the micropropagated plants. This is the first report for micropropagation of Z. armatum . Following further field trials, the protocol can be used for raising quality planting material for commercial cultivation which should also help in its conservation.