Abstract:[Background] Ectomycorrhiza is a symbiosis between ectomycorrhizal fungi and host plant by mycelium infection. It is an important approach for Pinus sylvestris var. mongolica to adapt environmental change and stress. [Objective] To explore a deeply insight on the ectomycorrhizal fungal community composition and diversity in P. sylvestris plantations. [Methods] A chronosequence of plantations (27 years old, 33 years old and 44 years old) were selected in the Mu Us Sandy Land. The community composition of ectomycorrhizal fungi associated with P. sylvestris were identified using the rDNA ITS segment PCR amplification sequencing, and diversity index was calculated. [Results] The 56 obtained OTUs were assigned to 2 phyla, 3 classes, 8 orders, 15 families and 21 genera. The predominant genera were Tomentella, Geopora and Amphinema. The highest richness and alpha diversity index were detected in the 27 and 33 years old plantations, respectively. However, no significance occurred in the three plots (P>0.05). The community composition of ectomycorrhizal fungi was quite different in the plantations affected by the variations in Geopora, Tomentella, Delastria and Mallocybe. [Conclusion] Ectomycorrhizal fungi associated with P. Sylvestris are abundant in the Mu Us Sandy Land. Community composition rather than diversity may indicate the dynamic changes of ectomycorrhizal fungi community with age in the Mu Us Sandy Land. With the sang ageing, the variations in functional ectomycorrhizal fungi potentially contribute to the P. sylvestris plantations degradation. This knowledge gap needs future exploration.
