In vitro asymbiotic germination of mature seed of medicinal orchid (Orchis simia Lam.)

The sexual reproduction of orchids is a notably slow process. This is due to their seeds lacking endosperm, which necessitates a fungal elicitor for germination in natural conditions. In the current study, we evaluated seed germination and the initial development of the protocorm of Orchis simia, an important medicinal orchid species, using a completely randomized design with three replications. The tetrazolium test revealed that 35% of the seeds were viable. Subsequently, we investigated the influence of casein, activated charcoal, indole acetic acid (IAA), photoperiod, and temperature on the germination of O. simia seeds. The analysis of variance demonstrated varying responses in terms of seed germination percentages, with photoperiod and temperature treatments having a more pronounced impact on germination. The optimal conditions for asymbiotic orchid seed germination in this experiment were achieved using Murashige and Skoog’s (MS) medium supplemented with one-fifth of nitrate concentration, casein (2.0 g/l), activated charcoal (2.0 g/l), and an IAA growth regulator (1.0 mg/l), resulting in a germination rate of 31%. After a three-month period, the nodes underwent transformation into protocorms. The findings presented in this report can serve as valuable insights for the production of orchid plants and the conservation of this medicinal species.