【摘要】 生物育苗基质、生物有机肥均可以通过其含有的植物根际促生菌(PGPR)来优化根际微生物组，从而促进作物生长。本研究旨在探究在2种施用策略(生物育苗基质和生物有机肥)下，双物种PGPR菌剂对西瓜生长及根际细菌群落的影响，从而为设施农业的发展提供技术支撑。设置如下4个盆栽试验处理：普通育苗基质+普通有机肥(OSOF)、普通育苗基质+生物有机肥(OSBF)、生物育苗基质+普通有机肥(BSOF)、生物育苗基质+生物有机肥(BSBF)。结果表明，与OSOF处理相比，OSBF处理对西瓜生长、根际细菌群落的影响不明显；BSBF处理能改变根际细菌群落的多样性，优化其结构与组成，显著增加西瓜植株株高、地上部生物量和地下部生物量。在BSOF处理下，鞘氨醇单胞菌科(Sphingomonadaceae)等若干潜在有益细菌类群的相对丰度显著提高，或被随机森林模型预测为该处理的关键类群，其中，鞘氨醇单胞菌属(Sphingomonas sp.)是预测西瓜促生效应的重要因子。PICRUSt2功能预测结果显示，与OSOF、OSBF处理相比，BSOF、BSBF处理的辅因子与维生素代谢、其他氨基酸代谢、膜转运及信号转导等相关功能的相对丰度显著提升。综上，在首次施用双物种PGPR菌剂时，应优先选择生物育苗基质策略，能够更高效地优化根际细菌群落结构并促进西瓜生长，并且与生物有机肥联用的效果更佳。更多还原

【Abstract】 Both biological seedling-raising substrates and biological organic fertilizers can optimize the rhizosphere microbiome through the plant growth-promoting rhizobacteria(PGPR) they contain, thereby promoting crop growth. This study aimed to explore the effects of a dual-species PGPR inoculant on watermelon growth and rhizosphere bacterial communities under two application strategies(biological seedling-raising substrates and biological organic fertilizers), so as to provide technical support for the development of facility agriculture. The pot experiment was set up with the following four treatments: ordinary seedling-raising substrate + ordinary organic fertilizer(OSOF), ordinary seedling-raising substrate + biological organic fertilizer(OSBF), biological seedling-raising substrate + ordinary organic fertilizer(BSOF), biological seedling-raising substrate + biological organic fertilizer(BSBF). The results showed that compared with the OSOF treatment, the OSBF treatment had no obvious impact on watermelon growth and rhizosphere bacterial communities. The BSBF treatment altered the diversity of rhizosphere bacterial communities, optimized their structure and composition, and significantly increased the plant height, aboveground biomass, and underground biomass of watermelon plants. Under the BSOF treatment, the relative abundances of several potentially beneficial bacterial taxa, such as Sphingomonadaceae, were significantly increased, or were predicted as key taxa for this treatment by the random forest model. Among them, Sphingomonas sp. was identified as an important factor for predicting the growth-promoting effect on watermelon. The PICRUSt2 functional prediction results revealed that compared with the OSOF and OSBF treatments, the relative abundances of functions such as cofactor and vitamin metabolism, other amino acid metabolism, membrane transport, and signal transduction in the BSOF and BSBF treatments were significantly increased. In conclusion, when applying the dual-species PGPR inoculant for the first time, the biological seedling-raising substrate strategy should be given priority, as it can more efficiently optimize the rhizosphere bacterial community structure and promote watermelon growth, and the effect is even better when combined with biological organic fertilizers.更多还原