Study on phyllosphere microbial community diversity of poplar

Abstract

Poplar is the core tree species for ecological protection forests and artificial afforestation in northern China, and it holds significant ecological and economic value. Phyllosphere microorganisms that colonize leaf surfaces play a crucial role in regulating plant growth, disease resistance, and environmental adaptation. This study aims to reveal the differences in phyllosphere microbial communities among different poplar varieties and to clarify the driving mechanisms of leaf nutrients on microbial community assembly. The study focused on four hybrid poplar varieties in Xinmin City, Liaoning Province. Leaf total carbon, total nitrogen, total phosphorus, soluble sugar, and starch contents were measured. High-throughput sequencing technology was used to identify the taxonomic composition of phyllosphere bacteria and fungi, analyze diversity differences among varieties, and explore correlations between leaf nutrients and microbial communities using statistical methods. Significant differences in leaf nutrient contents were detected among the four poplar varieties. The dominant microbial groups in the phyllosphere were overall stable: fungi mainly belonged to the phyla Ascomycota and Basidiomycota, while bacteria mainly belonged to Proteobacteria and Actinobacteria. However, species richness and community composition differed significantly among varieties. Correlation analysis revealed that leaf total nitrogen and total phosphorus were the key nutrient factors shaping phyllosphere microbial community composition. This study confirms that phyllosphere microbial communities of different poplar varieties exhibit obvious host specificity. Leaf nutrients are important driving factors regulating community structure. These findings provide a scientific basis for the management of artificial poplar forests and the utilization of microbial resources.