Morphophysiology and Cryopreservation of Seeds of Dendrobium Nobile Lindl. (Orchidaceae) at Different Stages of Development
Abstract We studied the seed maturation of Dendrobium nobile Lindl to establish the optimal stage for green pod culture and long-term storage in liquid nitrogen. It was found that the immature seeds can germinate in vitro starting from 3 months after pollination (MAP) but only develop up to the stage of embryo swelling or protocorm without rhizoids. The maximum staining of embryos with vital dyes FDA and TTC occurs at 4 and 5 MAP that corresponds to the release of suspensor beyond the embryo sac. Embryo staining does not correlate with germination capacity and seed viability in cryogenic storage. The immature seeds acquire resistance to freezing and drying in airflow at the age of 6 MAP. The time of technical maturity for green pod culture and cryopreservation may be reduced from 12 MAP to 6–7 MAP.