为探索甜玉米/鲜食大豆间作系统地下交互作用，本研究利用MiSeq高通量微生物测序技术，研究了甜玉米/鲜食大豆间作2:2和2:3种植模式下（分别以Ⅰm2s2和Ⅱm2s3表示）土壤氮磷代谢关键菌群固氮细菌和丛枝菌根真菌的组成和变化，分析了两类微生物群落变化与甜玉米产量的关系。结果发现，甜玉米/鲜食大豆间作处理显著优化了土壤固氮细菌的组成，与甜玉米单作处理相比，间作处理显著降低了固氮菌群中变形菌门未分类物种Proteobacteria_unclassified的相对丰度，却显著提高α-变形菌纲固氮菌属Aztobacter，α-变形菌纲根瘤菌目未分类物种Rhizobiales_unclassified和α-变形菌纲慢生根瘤菌属Bradyrhizobium的相对丰度。间作模式不同，土壤固氮细菌组成也不同，Ⅰm2s2对α-变形菌纲固氮菌属Aztobacter，α-变形菌纲根瘤菌目未分类物种Rhizobiales_unclassified和α-变形菌纲慢生根瘤菌属Bradyrhizobium相对丰度的提高显著低于Ⅱm2s3。间作处理并未改变丛枝菌根真菌群落多样性指数(Shannon指数)，却显著提高了丛枝菌根真菌群落丰度指数(Chao指数)，提高了球囊菌门Glomeromycota相对丰度。与甜玉米单作比，间作处理对固氮细菌和丛枝菌根真菌的优化有利于增强间作系统地下根系与氮磷代谢关键菌群的共生交互，显著地增加了土壤中碱解氮和有效磷的含量，提高了甜玉米产量。Ⅱm2s3模式在优化氮磷代谢菌群结构和促进甜玉米生长等方面优于Ⅰm2s2。本研究为甜玉米/鲜食大豆间作优势的发挥、农艺措施的合理优化配置提供了科学依据。

To investigate the underground interactions in sweet maize/vegetable soybean interplanting system, the community compositions of nitrogen-fixing bacteria and arbuscular mycorrhizal fungi under two planting modes of maize/soybean intercropping 2:2 and 2:3 (Ⅰm2s2 and Ⅱm2s3) were studied using MiSeq high-throughput sequencing technology, and the relationship between the two kinds of microbial community changes and sweet maize yields was analyzed in this study. The results showed that the sweet maize/vegetable soybean interplanting system significantly optimized the composition of nitrogen-fixing bacteria in soil. Compared with sweet maize monoculture, the sweet maize/vegetable soybean interplanting system significantly reduced the relative abundance of Proteobacteria_unclassified and significantly increased the relative abundance of Aztobacter, Rhizobiales_unclassified and Bradyrhizobium. The composition of soil nitrogen-fixing bacteria was also different in different intercropping patterns. The intercropping pattern Ⅱm2s3 significantly increased the relative abundance of Aztobacter, Rhizobiales_unclassified and Bradyrhizobium than the pattern Ⅰm2s2. All intercropping patterns did not have any effect on the Shannon diversity index of arbuscular mycorrhizal fungi community, but significantly increased the fungi abundance index (Chao index) and the relative abundance of Glomeromycota. Compared with sweet maize monoculture, the optimization of nitrogen-fixing bacteria and arbuscular mycorrhizal fungi communities by intercropping patterns could enhance the symbiotic interaction between root system, significantly increased the contents of available nitrogen and available phosphorus in soil, and increased sweet maize yield. The intercropping pattern Ⅱm2s3 was superior to Ⅰm2s2 in optimizing the structure of nitrogen-fixing bacteria and arbuscular mycorrhizal fungi communities and promoting the growth of sweet maize. The research results could improve the scientific basis for the intercropping advantages and adopt appropriate agronomic measures.

浙江省农业新品种选育重大科技专项(2021C02064-4-4)、粮食新品种选育协作组(2019ZX006-4)