Recovery of mycorrhizal fungi from wild collected protocorms of Madagascan endemic orchidAerangis ellisii(BS Williams) Schltr. and their use in seed germination in vitro

摘要

Orchid mycorrhizal fungi (OMF) are critical for seed germination and maintaining natural populations of orchids, yet the degree of specificity of most orchids to their mycorrhizal associates remains unknown. Many orchids are at risk of extinction, whether generalists or specialists, but orchid species of narrow fungal specificity are arguably under increased threat due to their requirement for specific fungal symbionts. This study characterises the fungi associated withAerangis ellisii, a lithophytic orchid from a site in the Central Highlands of Madagascar. Culturable OMF isolated from spontaneous protocorms of this species from the wild were used for seed germination. In vitro germination and seedling development ofA. ellisiiwere achieved with fungi derived fromA. ellisiiand an isolate from a differentAerangisspecies 30 km away. The significance of these findings and their importance to conservation strategies for this species and otherAerangisspp. is discussed. These results have important implications for the conservation ofA. ellisiipopulations in Madagascar.