ABSTRACT

Microorganisms are important in maintaining soil quality and contribute to plant nutrient uptake and pathogen resistance. However, intensive tillage and inappropriate fertilizer management distorts these important functions. This study therefore investigates the influence of tillage practices and P-fertilizer management on plant beneficial bacteria. The bacterial communities were profiled using DNA metabarcoding. Actinobacteria (40%) and Proteobacteria (21%) were the most abundant phyla in both the No-tillage (NT) and Conventional-tillage (CT) treatments. Alpha diversity analysis revealed that differences in P application influenced diversity. The bacterial community structure was significantly impacted by tillage practices. Plant beneficial bacteria including Lysobacter, Dyella, Sphingomonas and Dactylosporangium were among biomarkers in the NT treatment. Pathways for energy metabolism and the biosynthesis of siderophores were significantly influenced by both P-fertilizer application and tillage practices. Co-occurrence analysis revealed that the CT treatment reduced the efficiency of the bacterial communities while keystone species with potential for plant pathogen suppression were more in the NT treatment. Overall, this study demonstrates that tillage practices induce bacterial compositional changes, with the NT treatment exhibiting greater potential in promoting the stability and proliferation of plant beneficial bacteria, while P fertilizer influences diversity and community putative functions, regardless of tillage practice.

摘要

微生物对维持土壤质量很重要，有助于植物养分吸收和病原体抗性。然而，集约化耕作和不当的肥料管理扭曲了这些重要功能。因此，本研究调查了耕作方法和磷肥管理对植物有益细菌的影响。使用 DNA 元条形码对细菌群落进行了分析。在免耕 (NT) 和常规耕作 (CT) 处理中，放线菌 (40%) 和变形菌 (21%) 是最丰富的门。Alpha多样性分析表明，磷应用的差异影响多样性。细菌群落结构受到耕作方式的显着影响。植物有益细菌包括溶菌属、Dyella、鞘氨醇单胞菌和Dactylosporangium是 NT 治疗中的生物标志物之一。能量代谢途径和铁载体的生物合成受到磷肥施用和耕作方式的显着影响。共现分析表明，CT 处理降低了细菌群落的效率，而具有植物病原体抑制潜力的关键物种在 NT 处理中更多。总体而言，这项研究表明，耕作方法会引起细菌组成的变化，NT 处理在促进植物有益细菌的稳定性和增殖方面表现出更大的潜力，而 P 肥会影响多样性和群落推定功能，而与耕作方法无关。