Production of virus-free orchid Cymbidium aloifolium (L.) Sw. by various tissue culture techniques

Orchids are affected by many viruses resulting in poor growth, yield and quality, and an overall decline in population. Cymbidium mosaic virus (CymMV) is one of the common orchid viruses found in Cymbidium species but it infects different orchid genera. In this study Cymbidium aloifolium was propagated in vitro using MS medium at different strength (1.0, ½, and ¼) with or without 0.5 mg/l BAP (6-benzylaminopurine) and 0.5 mg/l NAA (Naphthalene acetic acid). To provide disease-free planting material, source plant for in vitro propagation needs to be screened for pathogenic viruses. In the present study, in vivo-grown source (mother) plants and tissue culture-derived plants of C. aloifolium were tested for CymMV virus using Double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA). All the tissue cultured plants were found to be 100% virus-free whereas the in vivo grown source plants were highly affected by CymMV virus (83.33%). The virus-free in vitro plantlets were multiplied in large scale and then acclimatized on earthen pot containing a mixture of cocopeat, litter and clay in the ratio of 3:2:1. Eighty five percent of acclimatized plantlets survived making this method an efficient mass production system for high quality virus-free C. aloifolium for commercial floriculture and germplasm preservation.