This study employed metagenomic sequencing technology and multivariate statistical methods to systematically analyze the spatial distributions and environmental driving factors of eukaryotic microbial communities, as well as their nitrogen metabolism genes at 15 sites along the Ba River. The results indicated significant differences in the α diversity of eukaryotic microbes among the upper, middle and lower reaches, with higher diversity in the lower reaches rather than that in the upper reaches. In terms of community composition, Bacillariophyta (48.3%) was the dominant phylum, and the relative abundance of Ciliophora remarkably increased in the middle and lower reaches. Nitrogen metabolism in eukaryotes was dominated by assimilation in the upper reaches, with a gradual increase in the abundance of transport-related genes in the middle reaches, and denitrification intensified in the lower reaches. Furthermore, TP, NO₃^⁻-N and NH₄^⁺-N significantly affected the eukaryotic microbial community structure, while NH₄⁺-N, NO₃^⁻-N, Chl a, COND and salinity were the key factors driving the distribution of nitrogen metabolism genes. 

综合运用宏基因组测序技术和多元统计的方法, 系统地分析灞河15个断面的真核微生物群落结构及其氮代谢基因的空间分布特征和环境驱动因素。结果表明, 灞河上、中、下游真核微生物的α多样性呈现显著差异, 且下游河段的真核多样性显著高于上游河段。在群落组成方面, 硅藻门(Bacillariophyta, 48.3%)为优势类群, 中下游河段的纤毛亚门(Ciliophora)丰度显著增加。真核生物的氮代谢功能在上游河段以同化作用为主导, 中游河段转运相关基因丰度逐渐升高, 下游河段则是反硝化作用增强。此外, 总磷、铵氮和硝态氮显著地影响真核微生物群落结构, 铵氮、硝态氮、叶绿素a、电导率和盐度是氮代谢基因分布的关键性驱动因子。