Ex situ conservation and enhanced secondary metabolite production in Adhatoda vasica L. and Andrographis paniculata (Burm.f.) Nees through optimized in vitro multiplication and elicitation protocols

AbstractAdhatoda vasica L. and Andrographis paniculata (Burm.f.) Nees are the two important medicinal plants which are facing threats due to overexploitation and habitat loss. This comprehensive study aimed to develop optimized plant tissue culture protocols for the ex-situ conservation of these species. Multiple explant types, culture media compositions, plant growth regulators, and elicitors were systematically evaluated to establish efficient micropropagation systems. For A. vasica, petiole explants on SH medium with 0.25 mg/L TDZ and 0.25 mg/L NAA yielded the highest shoot regeneration (89.9%) with 6 shoots per callus. For A. paniculata, stem explants on MS medium with 0.5 mg/L NAA and 2.0 mg/L BA produced 100% callus induction and 73.3% shoot regeneration. Elicitation with 5 mg/L chitosan enhanced biomass and secondary metabolite production in both plants. The optimized protocols enable rapid, large-scale propagation while conserving genetic resources. This research provides a foundation for the sustainable utilization and preservation of these valuable medicinal plants.