Microbial Community Structures and Diversity in the Rhizosphere Soil of Meconopsis Baileyi at Different Altitudinal Gradients

A study on Sejila Mountain in Xizang, China, found that rhizosphere microbial communities associated with Meconopsis baileyi vary with elevation, with fungi showing clearer differentiation than bacteria. Microbial co-occurrence networks were also more tightly connected at higher elevations. These findings offer insights into the growing environment of this alpine plant, known for its blue or purple flowers, and provide a basis for investigating suitable soil conditions and potentially beneficial microorganisms for cultivation.

The research was conducted by Xizang Agricultural and Animal Husbandry University and the Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences. Yongxia Wang is the first author, and Zhen Xing and Zhiyong Ruan are the corresponding authors. The paper was published online in Acta Microbiologica Sinica on May 29, 2026, and appears in volume 66, issue 10. In July 2023, the team collected rhizosphere soil—the soil immediately surrounding plant roots—at six elevations between 3,400 and 4,100 m, with three replicates per elevation. High-throughput sequencing and soil physicochemical analyses characterized the microbial communities and their environmental associations.

“Altitude exerted a more significant shaping effect on the fungal community structure,” the authors write in the paper. The Shannon diversity index, which reflects the variety and evenness of community members, differed significantly among elevations for fungi but not for bacteria. Bacterial richness declined sharply at 4,100 m. Fungal richness generally increased with elevation, although differences among elevations were not statistically significant.

Dominant microbial groups also varied with elevation. Pseudomonadota was the dominant bacterial phylum, with its mean relative abundance declining from 54.70% in the lower-elevation group to 40.63% in the higher-elevation group. Ascomycota was the dominant fungal phylum, and its relative abundance generally declined with increasing elevation. Higher-elevation co-occurrence networks featured more prominent core taxa, suggesting possible cooperative coexistence. These statistical associations, however, do not establish direct microbial cooperation or plant growth promotion.