Characterization of Bioactive Compounds at Seedling Stage and Optimization of Seed Germination, Culture Multiplication of Dendrobium nobile Lindl.-A Study In Vitro

An efficient protocol was developed for the characterization of bioactive molecules in in vitro raised cultures of medicinally important herb Dendrobium nobile. The cultures were initiated in vitro through asymbiotic seed germination technique on a defined Mitra medium (M) medium supplemented with plant growth regulators (PGRs) [6-benzyladenine (BA - 4.44 ?M), furfuryl aminopurine (Kn-4.65?M) and ?-naphthalene acetic acid (NAA- 5.37?M)].The frequency and onset of germination was markedly influenced by the presence of growth regulators in the nutrient medium. Seedlings were formed within 13.25 ± 0.50 weeks in NAA supplemented medium. The efficacy of growth supplements such as banana homogenate (Bh - 10, 20, 30 gl-1) and coconut water (CW -10, 20, 30%) was also tested on the multiplication (neo-formations) of the protocorms. Highest percentage of regeneration (80.25 ± 0.20%) and a maximum of 10.00 ± 0.40 protocorm-like bodies (PLBs) / explants formed in CW (20%) treated cultures and PLBs multiplied profusely. Plantlets developed within 14.00 ± 0.40 weeks. Bh (20 g l-1) favoured development of healthy plantlets with a maximum fresh weight of 1.030 ± 0.021 grams. Simultaneously, a method was developed for the characterization of bioactive molecules in extremely medicinal D. nobile herb by using high performance liquid chromatography (HPLC) coupled with electrospray ionization mass spectrometry. The analytical method was developed on X Terra MS C-18 column (250 mm × 4.6 mm, 5µm) by using acetonitrile: water (0.1% formic acid) 10:90 as mobile phase with flow rate of 1 ml min-1. Eleven compounds were identified in the in vitro grown seedlings. Therefore, the established quality evaluation method was successfully used for evaluating the quality of D. nobile samples of seedlings. Further, the reported methodology can open up avenues for its application in numerous orchidaceous plants of medicinal value prevailing in the Indo-Himalayan region.