Abstract

Orchids require mycorrhizal fungi (OMF) for their germination and growth. Propagation and re-introduction initiatives would likely require inoculation with such fungi. All Chilean Orchidaceae species are terrestrial and likely associate with OMF. We collected adult individuals of the endemic Chilean orchidChloraea gaviluand transported them to a glasshouse where we obtained mature capsules through manual auto-pollination. We asymbiotically germinated seeds in vitro using Malmgren Modified Terrestrial Orchid-Medium (MM). Embryos were put in glass flasks with MM where roots and leaves developed for 16 weeks. Plants were then transplanted to 165 mL pots and randomly separated into three groups; plants inoculated separately withCeratobasidiumOMFs isolated from two Chilean orchid species (Chloraea virescensandCodonorchis lessonii), and uninoculated (control) plants. Plants were then put in a growth chamber. Three months later, inoculated individuals showed pelotons inside parenchyma cells in the roots. Four months after inoculation, mycorrhizal plants had higher root and shoot biomass compared to control plants. At the end of the experiment, the highest mycorrhization was achieved with theCeratobasidiumstrain isolated fromC. lessonii. The artificial mycorrhization of endemic orchids could be a key strategy for future conservation and propagation initiatives, especially for endangered or commercially interesting species.