Asymbiotic germination in three Chloraea species (Orchidaceae) from Chile

Resumo

Orchids require symbiotic fungi and/or specific conditions to germinate. Asymbiotic techniques have been shown successful for orchid germination. In Chile, Chloraea include many endemic, and potentially ornamental, terrestrial orchid species. In this study, individuals of Chloraea crispa, C. gavilu and C. virescens were manually autopollinated. The resulting capsules were sterilized and seeds were aseptically obtained. We evaluated asymbiotic germination in: Agar Water (AW), Knudson C (KC), Banana Culture Media (CMB), Tomato Culture Media (CMT), Malmgren Modified (MM), Murashige and Skoog (MS), and MS modified (MS1/2). Seeds were incubated in the dark at 24±1 ºC for 2 weeks. Then they were put in 16/8 h light/dark cycles for 14 weeks. We registered germination and embryo development in the different culture media. After 8 weeks, all tested Chloraea species germinated in most culture media. After 16 weeks, embryos in MM showed an evident shoot. In AW only the pre-germination stage was achieved. In C. gavilu germination was over 90% in MM, CMT, and CMB. In KC, a lower germination was obtained in all tested species compared to the other culture media, except for AW. Asymbiotic germination of endemic Chilean orchids could be a viable strategy for their conservation and propagation as ornamental species.