Induced mutation on Indonesian black orchid (Coelogyne pandurata Lindley) in-vitro culture by gamma irradiation

Abstract

The black orchid (Coelogyne pandurata Lindley) is one of the native Indonesian orchid species. In its natural habitat, its existence is threatened by continuous forest exploitation. Coveted in the global market for hybridization purposes, the black orchid is still considered difficult to be grown in cultivation and may take years to flower. Its conservation and breeding may be carried out through a combination of tissue culture and mutagen application, as induced mutation may increase genetic variation. This experiment aims to investigate the effects of different levels of gamma irradiation on black orchid plantlets. The research design used is a complete random design, utilizing six levels of gamma irradiation (0, 5, 10, 15, 20, and 25 Gy). The observation was carried out for survival rate, number of leaves, number of roots, number of shoots, leaf color, and plantlet type. Plantlets of 10 Gy have the best survival rate and the number of new shoots, but the only number of leaves in the 5 Gy dose is significantly higher than the control. Plantlet growth of 25 Gy is nearly all stagnated. Root growth is also significantly reduced in plantlets of 15 Gy and above. The largest morphological changes are found in 10 and 15 Gy, therefore this range is recommended for future mutation breeding research of black orchids.