Mycorrhizal Diversity Associated to Liparis japonica (Miq.) Maxim. in China

Orchidaceae (Orchidaceae) is the second largest family of angiosperms. It’s the "flagship" group in plant protection. The existence of orchid plant is closely related to mycorrhizal fungi. The relationship between orchids and their symbiotic mycorrhizal fungi is a benefit to the protection and population restoration of orchids.

Aims: The research was aimed to study molecular identification about 15 strains of mycorrhizal fungi from 6 plots by rDNA ITS technology in order to understand and utilise the mycorrhizal fungi of Liparis japonica (Miq.) Maxim.

Study Design: The mycorrhizal fungi collected from different geographical locations were isolated and purified from the mycorrhizal fungi symbiotic with Liparis japonica in Northeast China, which were identified by rDNA ITS, meanwhile computed evolutionary distance and constructed the phylogenetic tree.

Place and Duration of Study: In 2017, the root segments of Liparis japonica were collected separately from Qianshan, Changbaishan, Gaoguan, Guanmenshan, Dongling, Daqinggou.

Methodology: Fifteen strains of mycorrhizal fungi collected from six plots were identified by rDNA ITS. Using DNAMAN software to analyse, the pairwise homology was compared by using the optimal global sequencing option. The evolutionary distances of fifteen strains were calculated by MEGA (Molecular Evolutionary Genetics Analysis) software package and their phylogenetic trees were constructed by neighbour-joining method.

Results: With primers ITS1 and ITS4, the 15 mycorrhizal fungi strains of rDNA ITS got about 600 bp length. ITS length was about 582-613 bp, in which ITS1 length was about 177-190 bp, and ITS2 length was 246-273 bp. The mycorrhizal fungi strains were highly homology separated from one plot, mostly above 90%. The plots from the south to the north were as follows: Qianshan, Guanmenshan, Gaoguan, Dongling, Changbaishan, Daqinggou in China. Fifteen strains after separated and purified were identified to be the Epulorhiza of Orchid Rhizoctonia blasted with Genbank. The homology of the strains gradually decreased affected by the difference of the north and the south, namely there was an increasing trend of diversity from south to north.

Conclusion: The homology of mycorrhizal fungi from one plot was higher because of the same soil environment and climate environment and so on, and strain type was single. Under the influence of microclimate in Northeast China, the homology of strains decreased gradually in the sample area, that is, the diversity gradually increased from the south to the north.