Genetic clonal fidelity assessment of rhizome-derived micropropagated Acorus calamus L. - A medicinally important plant by random amplified polymorphic DNA and inter-simple sequence repeat markers

Background: Acorus calamus - a critical medicinal plant, is overexploited, leading to population reduction. Establishing an efficient in vitro protocol is essential for the large-scale production of genetically identical plants. Objectives: Development of fast and reliable in vitro regeneration protocol for A. calamus and clonal fidelity assessment of the regenerants using molecular markers. Materials and Methods: Plants were regenerated on Murashige and Skoog medium with different concentrations of growth regulators in two phases - shooting and rooting. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were employed to evaluate the genetic stability of in vitro clones. Results: 6 Benzylaminopurine (BAP) at 1.6 and 2.4 mgL(-1) was effective for shoot induction, while root induction was superior in indole-3-butyric acid-incorporated medium at 2.5 mgL(-). Thirteen RAPD and 16 ISSR primers produced 59 and 96 clear, unambiguous, and reproducible bands, respectively. Both the markers revealed a high monomorphism of 96.79% and 95.63% among the regenerants. Nei's genetic distance analysis disclosed a close genetic association (0.000-0.068) among the genotypes. Conclusion: ISSR was better than RAPD markers in clonal fidelity assessment of the regenerants. The in vitro protocol developed is reliable and suitable for the rapid propagation of true-to-type A. calamus plants.

Automated summary

In this study, a reliable in vitro regeneration protocol was developed for the rapid propagation of Acorus calamus plants, and the clonal fidelity of the regenerants was assessed using molecular markers. The results indicated that ISSR markers were more suitable for clonal fidelity assessment compared to RAPD markers.