A Combinational Phytomolecular-Mediated Assessment in Micropropagated Plantlets of Coelogyne ovalis Lindl.: A Horticultural and Medicinal Orchid

Abstract

Coelogyne ovalis Lindl. is an evergreen epiphytic, sympodial, ornamental orchid having medicinal properties due to the presence of bioactive compounds such as flavidin, flavidinin, coelogin. In the present study, nodal buds of Coelogyne ovalis, when cultured in Knudson C medium supplemented with meta-Topolin (mT), 6-benzyl aminopurine (BAP), kinetin (Kn) and α-naphthalene acetic acid (NAA), responded to the induction of protocorm-like bodies (PLBs) or shoot buds. The highest numbers of PLBs (22.73 ± 0.47) and shoot (14.53 ± 0.27) per explant were augmented in the medium containing a combination of mT (10 µM) and NAA (0.5 µM). Meta-Topolin in the medium was found to be superior in enhancing the response of explants as compared to BAP and Kn. The best rooting of the shoots was observed in the medium supplemented with 10 µM indole-3-acetic acid. Well-developed plantlets obtained after 20 weeks of culture were acclimatized and transferred to the net house. Genetic stability of the acclimatized plantlets was evaluated and contrasted with the mother plant using two molecular markers, viz. start codon targeted and inter-simple sequence repeats, wherein 5.15% clonal variability was observed. Phytochemical screenings revealed that the micropropagated tissues exhibited higher contents of secondary metabolites, antioxidant potentials and chlorophyll contents as compared to the mother plant. The present study could be of great significance for the conservation and commercial utilization of C. ovalis, an orchid facing threat due to its overexploitation from nature.