Effect of light quality and plant growth regulator on organogenesis of orkid Cymbidium dayanum

Orchids include some of the world’s most important floricultural (cut-flower) and ornamental (pot and garden) plants (Teixeira da Silva, 2013). Cymbidium dayanum is important evergreen, epiphytic orchid which is valued for their attractive flowers. This species that is quite widespread from Northern India right through to Japan and is one of the most sought after ornamentals in local cut flower market. In recent years, the population of C. dayanum has declined rapidly due to unregulated heavy collection, excessive habitat destruction and deforestation. C. dayanum had been declared as vulnerable and threatened orchid in Red Data Book (Nayar and Sastry, 1990). There is an increasing risk of this important orchid becoming extinct from its natural habitat if uncontrolled exploitation continues unabated (Nongdam and Chongtham, 2012). Effective conservation strategies should be devised to prevent further loss of the already depleted of this orchid population. The in vitro approach through the application of plant tissue culture technology provides an excellent opportunity for effective conservation by mass propagating orchids in short time span. Though there are several reports on tissue culture of different orchids, the micropropagation of C. dayanum has been very less documented in the literature.