In Korea, the orchid species Cymbidium goeringii and C. kanran are very important as natural genetic resources and floriculture crops. With respect to nutrient uptake, both species mixotrophic, and can shift to autotrophy with the development of photosynthetic organs. In this study, microscope observation was performed to examine the existing symbiotic fungi and their pelotons in root cortical tissues. Molecular identification was performed to identify orchid mycorrhizal fungi (OMF) and evaluate phylogenetic relationships with other OMF taxa in the database. Essential molecular data encompassing ribosomal internal transcribed spacers (ITS) were amplified from the extracted genomic DNA of root tissues. The hyphae grown into cortical root tissues of two individual cymbidiums were observed and revealed to form typical coiled structures called pelotons. OMF sequences obtained from C. goeringii root tissues were determined to be 673 bp nucleotide sequences (MF101371), while those obtained from C. kanran root tissues were 788 bp nucleotide sequences (MF101372). The resulting ITS rDNA sequence was analyzed using the UPGMA cluster analysis method and a dendrogram was generated. According to the phylogenetic tree, the ITS rDNA sequence from C. goeringii was positioned among other Tulasnella species, and that from C. kanran was grouped with Russula species. Producing elementary, but fundamental, data about the nutritionally helpful symbiotic mycorrhizal fungi is very important to facilitate orchid-fungal microbe interactions and for cultivation and conservation programs for native orchids.

Abstract
 Introduction
 Materials and Methods
  Plant source and preparation for root microscopy observation
  Amplification of rDNA ITS region for molecular identification of mycorrhizal fungi
  Phylogeny construction for comparison among other orchid fungal isolates
 Results and Discussion
  Observation of the symbiotic state of mycorrhizal fungi in Cymbidium roots
  Molecular identification of orchid mycorrhizal fungi through the rDNA sequence analysis
 Conclusion
 References

• Sul Gi Lee(Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women’s University)
• Jong Suk Lee(Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women’s University, Useful Plant Resources Center, Korea National Arboretum)
• Sun Hee Choi(Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women’s University) Corresponding author