Abstract

Mycorrhizal interactions of orchids are influenced by several environmental conditions. Hence, knowledge of mycorrhizal fungi associated with orchids inhabiting different ecosystems is essential to designing recovery strategies for threatened species. This study analyzes the mycorrhizal associations of terrestrial orchids colonizing grassland and understory in native ecosystems of the region of La Araucania in southern Chile. Mycorrhizal fungi were isolated from peloton-containing roots and identified based on the sequence of the ITS region. Their capacities for seed germination were also investigated. We detectedTulasnellaspp. andCeratobasidiumspp. in the pelotons of the analyzed orchids. Additionally, we showed that someCeratobasidiumisolates effectively induce seed germination to differing degrees, unlikeTulasnellaspp., which, in most cases, fail to achieve protocorm growth. This process may underline a critical step in the life cycle ofTulasnella-associated orchids, whereas theCeratobasidium-associated orchids were less specific for fungi and were effectively germinated with mycorrhizal fungi isolated from adult roots.