The Bacterial Community Characteristics of Hippophae rhamnoides Subsp. sinensis Rousi in Different Distribution Areas of the Qinghai–Tibet Plateau and Their Responses to Habitat Factors

Investigating the compositional characteristics of rhizosphere soil bacterial communities of Chinese seabuckthorn across different distribution areas and their relationship with habitat factors holds significant value for the development and utilization of characteristic medicinal plant resources in the Qinghai-Tibet Plateau. This study targeted rhizosphere soil from 12 distribution areas of Chinese seabuckthorn on the Qinghai-Tibet Plateau. By integrating measurements of soil and climatic parameters with high-throughput sequencing and redundancy analysis (RDA), the research systematically elucidated the characteristics of rhizosphere bacterial communities and their environmental driving mechanisms. The results revealed that rhizosphere bacterial communities of Chinese seabuckthorn across all 12 distribution areas were dominated by Proteobacteria, Acidobacteriota, and Actinobacteriota. Among them, the R2 habitat exhibited the highest amplicon sequence variant counts (3496), while R1, R8, R9, and R12 habitats showed significantly lower counts. α/β diversity analysis revealed that Shannon, Ace, and Chao1 indices in R2 and R7 habitats were significantly higher than those in R1 and R8. Regarding community aggregation patterns, soil bacterial communities in R1, R9, and R12 habitats exhibited the highest aggregation, while those in R2 and R11 habitats showed relatively lower aggregation. Functional prediction demonstrated that Metabolism dominated across all distribution areas (50.40-52.02%), with the R11 habitat exhibiting exceptionally high metabolic function abundance (>9300). Clustering analysis partitioned the 12 habitats into two distinct groups: one comprising R2, R6, R7, R9, R10, and R11, and the other containing the remaining six habitats. Redundancy analysis (RDA) further clarified that habitat factors, including altitude, soil water content (SWC), east longitude (EAST), and pH, were key drivers shaping bacterial community structure. This study underscores the pivotal regulatory role of environmental factors in shaping rhizosphere microbial diversity, community structure, and functional profiles of Chinese seabuckthorn, thereby providing a valuable scientific foundation for the sustainable development of characteristic medicinal plant resources on the Qinghai-Tibet Plateau.