Efficient plant regeneration of the endangered medicinal orchid, Coelogyne cristata using protocorm-like bodies

Abstract

An efficient method of Coelogyne cristata mass propagation was developed using segment of protocorm-like bodies (PLBs) (3 mm2 in size). It was observed that ½ MS medium showed to be more effective to induce shoots through PLBs segment. The explants when cultured on ½ MS media containing TDZ and CP showed relatively superior effect on shoot regeneration as compared to the media containing TDZ alone or in combination with BP. Addition of BP and CP to the medium containing NAA and BA combinations proved distinctly better for shoot multiplication than that of the medium with NAA and BA combinations alone. The highest percentage of explants producing shoots, with a maximum average of 8.1 per explant, was induced on the medium supplemented with 1.0 mg l−1 NAA and 0.5 mg l−1 BA with CP. Shoots produced an average of 15 roots per explant on ½ MS medium supplemented with 2.0 mg l−1 IBA and BP. The 4 cm height plantlets with well-developed roots were successfully acclimatized. The results suggest that CP and BP can be used effectively to initiate shooting and rooting of Coelogyne cristata. Ploidy analysis of regenerated plants using flow cytometry revealed the same ploidy level (diploid). This efficient and reliable protocol could be useful for mass multiplication and germplasm conservation of the wild medicinal orchid.