Microbial Community Structure Diversity of Male and Female Poplar Plants of the Same Faction and Its Influencing Factors

Phyllosphere microorganisms interact with host plants to regulate growth, promote nutrient uptake and enhance stress tolerance with host specificity, while arbuscular mycorrhizal fungi facilitate plant nutrient absorption and stress adaptation. Current poplar microbial studies mostly focus on hermaphroditic species, with limited research on dioecious poplars. This study selected four poplar species commonly hybridized with Populuscathayana and Populus deltoides in the Xinmin area of Liaoning Province as research subjects: two female plants, DM-9-18 and DX-08-01, and two male plants, 2111 and Qingshan poplar. We performed MiSeq high-throughput sequencing targeting bacterial 16S rRNA, fungal ITS, and arbuscular mycorrhizal fungal (AMF) marker genes from poplar phyllosphere, coupled with chemical quantification of leaf, root and rhizosphere soil, to disentangle clone- and sex-associated divergence in microbial assemblages and their core environmental drivers. No significant gender differences were observed in leaf and rhizosphere nutrient levels and microbial α diversity, whereas male poplars had higher rhizosphere soil nutrients. Male and female poplars genotypes harbored distinct microbial ASVs. The dominant phyllosphere microbes and arbuscular mycorrhizal fungi exhibited gender-specific abundance variations, and nutrient content was the key factor shaping microbial communities. This study clarifies microbial community differences among the four selected hybrid poplar clones. While the experimental design confounds sex with host genotype, the observed patterns provide insights into potential sex-related variations. Our results advance the mechanistic understanding of how dioecious poplar genotype and sexual phenotype jointly filter leaf and root-associated microbial symbionts, with applied implications for hybrid poplar breeding and shelterbelt microbial regulation.