硒对油菜根际土壤微生物的影响

为明确硒对土壤根际微生物生态特征的影响，采用盆栽试验，基于高通量测序技术研究了不同浓度（0、0.5、1.0 mg·kg^-1）外源硒对油菜根际土壤微生物群落结构与多样性的影响。群落结构分析结果表明：油菜根际土壤细菌优势菌门主要为变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、厚壁菌门（Firmicutes）和酸杆菌门（Acidobacteria）等；真菌优势菌门为子囊菌门（Ascomycota）。多样性分析结果表明，硒未显著影响土壤细菌和真菌群落的多样性。主坐标分析表明，硒处理对细菌群落结构具有显著影响，而对真菌群落的影响不明显。显著差异物种线性判别分析（LDA）显示：Microtrichales显著富集于低浓度（0.5 mg·kg^-1）硒处理土壤中；产黄杆菌（Rhodanobacter）、Nitrolancea、热微菌科（Thermomicrobiaceae）和无色杆菌属（Achromobacter）则显著富集于高浓度（1.0 mg·kg^-1）硒处理土壤中。研究表明，施硒有助于油菜根际土壤富集有益根际微生物，从而促进植物生长，提高植物应对不良环境胁迫的能力。

Effects of selenium on microorganisms in the rhizosphere soil of oilseed rape

Pot experiments were performed to investigate the effects of different concentrations(0, 0.5, and 1.0 mg·kg^-1)of exogenous selenium(Se)on the microbial community structure and diversity of rapeseed rhizosphere soil. The community structure analysis showed that the dominant bacteria in the rhizosphere of Brassica napus were Proteobacteria, Actinobacteria, Firmicutes, and Acidobacteria, and the dominant fungi were Ascomycota. The diversity analysis showed that exogenous Se did not significantly affect the diversity of the soil bacterial and fungal communities. The principal coordinate analysis showed that the Se treatments had a significant effect on the bacterial community structure, but not on the fungal community structure. Significant differences in the linear discriminant analysis(LDA)showed that Microtrichales was significantly enriched by the low Se concentration in the soil, and Rhodanobacter, Nitrolancea, Thermomicrobiaceae, and Achromobacter exhibited significant enrichment after treatment with the high concentration of Se in the soil. The results showed that Se treatments were beneficial for the enrichment of rhizosphere microorganisms in the soil of rapeseed, thus promoting plant growth and improving the ability of the plants to cope with adverse environment stress.