Asymbiotic seed germination and in vitro seedling development of Acianthera prolifera (Orchidaceae)

The effect of the culture medium and of the addition of sucrose and activated charcoal on in vitro germination and protocorms development of Acianthera prolifera was analysed in order to establish a protocol for the seedlings propagation and ensure their conservation. Murashige & Skoog (MS), MS with half the salt concentration (MS/2), Knudson C (KC), and Woody Plant Medium (WPM) culture media were tested for asymbiotic seed germination and plantlet development for 16 weeks. MS/2 was more efficient in the beginning of germination and WPM was more suitable for plantlet formation. Protocorms and plantlets developed more efficiently in WPM containing 1 g L− 1 activated charcoal. Culture media supplemented with sucrose promoted plantlet growth after a 12-week subculture and the recommended concentration of sucrose was 60 g L− 1 for WPM, and 15 g L− 1 for MS/2. Seed and protocorm anatomy was characterized until plantlet formation. The seedlings were successfully acclimatized (95%) in a commercial mixture of pine bark, coconut fibre, and activated charcoal combined with vermiculite (1:1) after 12 weeks of culture in a greenhouse.