Micropropagation, morpho-anatomical characterization, and genetic stability studies in Lippia javanica (Burm.f.) Spreng: a multipurpose medicinal plant

Lippia javanica is a multipurpose medicinal plant of the Verbenaceae family, which is commonly known for its volatile and essential oil compounds with numerous pharmaceutical applications. Due to medicinal importance, the plant was overexploited, which has been resulted in the rare availability of plant material. Through this study, an efficient and reproducible protocol was established for its in vitro micropropagation using nodal explants. Maximum number of shoots (7.11 ± 0.12) per nodal explant was induced on Murashige and Skoog (MS) medium augmented with 2.0 mg L −1 of 6-benzylaminopurine (BAP). When combination of phytohormones tested, highest number of multiple shoots (25.76 ± 0.37) was obtained on 2.0 mg L −1 of BAP and 0.5 mg L −1 of kinetin (Kn). Rooting of shoots with good response and maximum number of roots (21.19 ± 0.54) per explant was induced on half-strength MS medium with 1.0 mg L −1 of indole-3-butyric acid (IBA). Well rooted in vitro raised plantlets were hardened in paper cups possessing soilrite. The hardened plantlets were initially maintained in the pots for 3 weeks and finally acclimatized to soil conditions with an 80% of survival rate. The micro-morpho-anatomical characterization of in vitro and ex vitro hardened plantlets revealed detailed developmental information about structural features of leaf, stem, and the type and density of trichomes while adapting to natural conditions. Similarly, the genetic fidelity of micropropagated plantlets were screened by SCoT and ISSR molecular markers and the results confirmed the true to type nature of regenerated plantlets with the mother plant. Key message Lippia javanica is a multipurpose medicinal plant with substantial industrial demand. An efficient in vitro micropropagation protocol was established from nodal explants of Lippia javanica . It is the first report on micro-morpho-anatomical studies and genetic fidelity analysis using molecular markers in Lippia javanica .