The Diversity of Microorganisms in the Rhizosphere Soils of Kobresia humilis and Their Responses to Environmental Factors in the Source Region of the Yellow River
Abstract: To explore the composition characteristics of the microbial community in the rhizosphere soil of Kobresia humilis and the influencing factors of environmental factors. The rhizosphere soil of K. humilis at altitudes ranging from 3000 m to 5000 m in the Source Region of the Yellow River was adopted as the test material. Illumina MiSeq sequence and bioinformatics analysis were carried out on the rhizosphere fungi and bacteria to investigate the differences in microbial diversity, community structure, and their relationships with environmental factors in the rhizosphere soil. The results indicated that there were considerable differences in the relationships among microbial diversity, community structure, and environmental factors at five altitudes sites in the Source Region of the Yellow River. Among the rhizosphere soils at different altitudes, the fungal diversity was the highest at 4027.0 m, while the bacterial diversity was the highest at 4932.1 m, demonstrating distinct response patterns of fungi and bacteria to altitude variations. With the increase in altitude, both the richness and diversity of the fungal community decreased, while those of the bacterial community increased. The structure of the soil microbial community exhibited different changing patterns with the ascent of altitude.We found that the abundance of Olpidiomycota in the fungal community increased with increasing altitude, while Basidiobolomycota was only distributed at sampling sites higher than 4500 m. The phylum with increasing abundance were Nitrospirota, Bdellovibrionota, Elusimicrobiota, RCP2-54 and SAR324_cladeMarine_grou p_B, the door that gradually declines with altitude is Fusobacteriota. Among the soil environmental factors, the contents of nitrogen and organic matter were the highest at 4932.1 m, and the potassium content was the highest at 4027.0 m. The pH value decreased with the increase in altitude. RDA analysis demonstrated that available potassium and altitude were the significant influencing factors on the composition and diversity of the fungal community, while the bacterial community was more affected by pH, total nitrogen, total phosphorus, available nitrogen, organic matter, and altitude. Among them, pH had the most prominent impact on the bacterial community structure. This study conducted an in-depth analysis of soil microbial diversity, community structure, and their influencing environmental factors at different altitudes through Illumina MiSeq sequence technology, and providing a theoretical basis at the soil microbial level for the ecological protection in the Source Region of the Yellow River