Chiang Mai Journal of Science

The life cycle of Paphiopedilum, the lady’s slipper orchid, under natural conditions requires fungal symbiosis, especially during the stage of seed germination. For orchid propagation and conservation, endophytic fungal isolation and orchid root anatomical observation are fundamental stages for mycorrhizal studies. Here, endophytic fungi were isolated from the root of three endemic orchids from Southern Thailand; Paphiopedilum niveum, P. exul and P. godefroyae. Fungal identification was based on morphological and molecular data. Results showed that all orchids exhibited several root anatomical adaptations. Endophytic fungal colonisation in their roots consisted of peloton structures in root cells of the cortex layer. Seven endophytic fungi belonging to four different taxa including Tulasnella sp., Fusarium solani, Phomopsis sp. and Daldinia eschscholtzii were identified from three orchid species. The genus Tulasnella is the most common endophytic fungi, forming root associations in several terrestrial orchids. Endophytic fungi can be applied for orchid propagation for successful future conservation.