Ex Situ Conservation of Two Orchid Species Viz. Cymbidium Elegan Slindley. and Dendrobium Densiflorum Lindl. by Tissue Culture Technique

Abstract

Cymbidium elegans Lindley. and Dendrobium densiflorum Lindl. are two important orchids especially used for horticultural purposes. Both of these species are listed as rare and critically endangered (CITES, Appendix II)For the conservation and propagation of these species, the present study was conducted to determine the germination of both the species and invitro mass propagation of D. densiflorum Lindl. by using MS medium(Murashige and Skoog medium, 1962) and MS medium supplemented with different growth regulators. MS medium supplemented with BAP 1mg/l was the most effective for in vitroseed germination of C. elegans Lindley. in which germination started after 9 weeks of inoculation where as the MS basal medium was most effective for in vitro seedgermination of D. densiflorum Lindl. in which germination was startedafter 5 weeks of inoculation. Shoot tip and root tip explants obtained fromin vitrogrown seedling ofD. densiflorum Lindl. was cultured in MS basalmedium and MS supplemented with various combinations of BAP andNAA. The maximum number of healthy shoots was observed in MS +BAP 2 mg/l + NAA 0.5 mg/l medium (4.0 shoots/culture). The appropriate medium for root tip development was found tobe MS + BAP1.5 mg/l (7.25 shoots/culture). For rooting, shoot tip explants from invitromultiplied shoots of D.densiflorum Lindl. were rooted by using different concentrations of IAA, IBA and NAA. The rooting wasobserved after 10 weeks of culture of shoot tips. MS + IBA 1.5 mg/l (4.5roots/culture) was found to be more effective for maximum number and enlargement of roots. Thein vitropropagated plantlets were subjected for acclimatization.