In vitro asymbiotic seed germination and seedling development of four endangered Ecuadorian orchids: Epidendrum Jamiesonis, Pleurothallis pulchella, Oncidium pentadactylon, and Elleanthus capitatus

Abstract

Although Ecuador is one of the richest places in the world in terms of biodiversity of species belonging to the Orchidaceae family, some of its species are endangered. The main factors that are threatening orchid species include destruction of their habitat, inadequate management of resources, environmental contamination, and overcollection of specimens. Each orchid capsule contains thousands of seeds; however, only 2–3% germinate under natural conditions. The limited germination is attributed to factors such as the lack of seed endosperm and the need for symbiotic relationships with mycorrhizae. The in vitro orchid culture may be a strategy to achieve their efficient propagation and thus contribute to their conservation. This study reports protocols for in vitro seed germination in four species of Ecuadorian orchids: two epiphytic species, Epidendrum jamiesonis and Oncidium pentadactylon, and two terrestrials, Pleurothallis pulchella and Elleanthus capitatus. A germination percentage higher than 30% was observed in all species, which led to successful seedling development. For Epidendrum jamiesonis, effective elongation and acclimatization stages are also reported. The plants obtained from the in vitro asymbiotic culture described here could promote conservation programs and serve as a reference for the culture of other orchid species.