Abstract:

This paper investigates the fungal community diversity of Pinus sylvestris var. Mongolica needles under different degrees of disease, which can provide valuable information for the identification and control of foliar diseases. The needles of Pinus sylvestris var. mongolica were sampled, and the collected samples were analyzed for fungal community diversity by high-throughput sequencing technology. The fungi with high relative abundance were compared by BLAST, and phylogenetic trees were constructed and analyzed. The relative abundance of species in the nine conifer samples was mainly distributed among Ascomycota and Basidiomycota, and a minimal amount of Rozellomycota fungi were also present in the conifer. The Ascomycota was the dominant phylum with the largest relative abundance at the "phylum" level. The Mycosphaerellaceae accounted for 92%, 92%, and 29% of the heavy disease samples W3-3, T78-3, and T87-3 from three different forestry sites, respectively. It was found that there were some differences in the community composition structure of different forest sites, and different levels of incidence caused different evenness of species composition, indicating that the relative abundance of fungi after incidence was influenced by both the level of incidence and the geographical environment. The percentage of Dothistroma septosporum increased as the degree of incidence increased. A phylogenetic tree was constructed based on the ITS sequences of the pathogenic fungus, and the pathogenic fungus causing the Dothistroma pini Hulbary in the foliar parts of camphor pine in the three forest sites was confirmed to be D. septosporum.

Key words: Pinus sylvestris var. mongolica, High-throughput Sequencing, Dothistroma septosporum, ITS