title: Genetic stability and phytochemical analysis of the in vitro regenerated plants of Dendrobium nobile Lindl., an endangered medicinal orchid.
abstract: An efficient genetically stable regeneration protocol with increased phytochemical production has been established for Dendrobium nobile, a highly prized orchid for its economic and medicinal importance. Protocorm like bodies (PLBs) were induced from the pseudostem segments using thidiazuron (TDZ; 1.5 mg/l), by-passing the conventional auxin-cytokinin complement approach for plant regeneration. Although, PLB induction was observed at higher concentrations of TDZ, plantlet regeneration from those PLBs was affected adversely. The best rooting (5.41 roots/shoot) was achieved in MS medium with 1.5 mg/l TDZ and 0.25% activated charcoal. Plantlets were successfully transferred to a greenhouse with a survival rate of 84.3%, exhibiting normal development. Genetic stability of the regenerated plants was investigated using randomly amplified polymorphic DNA (RAPD) and start codon targeted (SCoT) polymorphism markers which detected 97% of genetic fidelity among the regenerants. The PIC values of RAPD and SCoT primers were recorded to be 0.92 and 0.76 and their Rp values ranged between 3.66 and 10, and 4 and 12 respectively. The amplification products of the regenerated plants showed similar banding patterns to that of the mother plant thus demonstrating the homogeneity of the micropropagated plants. A comparative phytochemical analysis among the mother and the micropropagated plants showed a higher yield of secondary metabolites. The regeneration protocol developed in this study provides a basis for ex-situ germplasm conservation and also harnesses the various secondary metabolite compounds of medicinal importance present in D. nobile.
authors.affiliation: Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong 793022, Meghalaya, India.
authors.forename: Paromik
authors.initials: P
authors.lastname: Bhattacharyya
authors.affiliation: Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong 793022, Meghalaya, India.
authors.forename: Suman
authors.initials: S
authors.lastname: Kumaria
authors.affiliation: Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong 793022, Meghalaya, India.
authors.forename: Reemavareen
authors.initials: R
authors.lastname: Diengdoh
authors.affiliation: Plant Biotechnology Laboratory, Department of Botany, Centre for Advanced Studies, North-Eastern Hill University, Shillong 793022, Meghalaya, India.
authors.forename: Pramod
authors.initials: P
authors.lastname: Tandon
keywords: Antioxidants; Genetic fidelity; In vitro propagation; RAPD; SCoT; Secondary metabolites