In vitro seed germination of an Endangered Terrestrial Orchid Species Geodorum densiflorum (Lam.) Schltr.

Abstract

Orchid seed is rather difficult to germination rather than other angiospermic seeds, because of lack radical and endosperm, leaf rudiments. Seed germination and protocorm like body (PBL) formation of Geodorum densiflorum (Lam.) Schltr. was performed. This study was conducted to determine the effects of coconut milk (CM), and BAP for optimal media culture. Seeds from sterilized capsules were cultured on two media and MS medium (Knudson C orchid medium, KnC, containing 0 and 25% (v/v) CM and 0 and 5 mgl BAP with 0.8% (w/v) agar as material. The cultures were solidifying provided by cool white florescent maintained tubes. The highest germination percentage was observation in 15% (v/v), CM and 3 mg l-1 BAP both in MS and KnC media. Seeds germinated and formed light green globular structures on the medium after three weeks of culture. These globular structures produced Protocorm-like body (PLB) and proliferated and developed into irregular-shaped rhizomes with white hairy structures. Highest in vitro seed was found in KnC medium supplemented with 15% CM and 3 mgl-1 BAP about 95.31 % whereas in MS medium maximum cultured germination KnC reached medium at 79% with 15% CM and 3 mg BAP. Overall, this study showed that Geodorum seeds culture on KnC medium containing CM and BAP can be used for clonal propagation.