[Objective] To explore the structural characteristics of microbial communities in the rhizosphere soil of Meconopsis baileyi along different altitude gradients. [Methods] This study employed high-throughput sequencing to investigate the microbial community composition and diversity in the rhizosphere soil of M. baileyi and conducted a correlation analysis on the microbial community characteristics with environmental factors. [Results] At different altitudinal gradients, there are significant differences in the common genera of bacteria and fungi in the rhizosphere soil of M. baileyi. The common genera at low altitudes are all greater than those at high altitudes, and show a downward trend with increasing altitude. Their diversity initially increased and then decreased with increasing elevation. Fungal species richness generally increased with elevation, whereas bacterial species richness also increased but declined sharply at 4 100 m. Pseudomonadota was the most dominant phylum among soil bacteria, and Ascomycota was the most dominant phylum among soil fungi. Their relative abundance generally showed a downward trend with the rise in altitude. Altitude exerted a more significant shaping effect on the fungal community structure. Although bacterial communities were also affected by altitude, the altitude specificity of taxonomic group distribution was weak, and diversity tended to be more stable.The co-occurrence networks of microorganisms at high altitude gradients were more compact, with core groups being more prominent, which indicated collaborative coexistence of microorganisms in extreme environments. In contrast, the networks at low altitude gradients were looser, with microorganisms surviving independently in suitable environments. Soil pH, electrical conductivity (EC), available phosphorus (AP), soil temperature (ST), and soil moisture content (SMC) were identified as the major drivers shaping microbial community structure across altitudinal gradients. [Conclusion] Altitude significantly affects the species composition and community distribution of rhizosphere microorganisms in M. baileyi. Diversity generally increased initially and then decreased with increasing elevation, whereas species richness showed an overall increasing trend; however, bacterial richness declined sharply at the highest elevation.The relative abundance of the dominant phyla of both communities generally decreases as altitude rises, and altitude has a more significant role in shaping the fungal community structure. In addition, the microbial co-occurrence networks are more compact at high altitudes but looser at low altitudes, with pH and EC acting as key environmental drivers of microbial community structure.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |