施肥对盐碱地饲用燕麦根际土壤微生物多样性的影响

Effects of the Fertilization on the Microbial Diversity in the Rhizospheric Soil of Forage Oats in Salt-alkali Land

为了探究不同施肥模式对盐碱地饲用燕麦(Avena sativa L.)根际土壤微生物多样性的影响,本文设置盐碱地饲用燕麦‘甜燕1号’不施肥、施用常规肥和控释肥模式,基于16S rRNA和内转录间隔区(Internal transcribed spacer,ITS)基因高通量测序技术分别对根际土壤细菌和真菌多样性进行生物信息学分析。结果显示,施肥比不施肥模式增加了根际土壤细菌和真菌的α和β多样性,其中控释肥模式下细菌和真菌群落的操作性分类单元(Operational taxonomic unit,OTU)数量最高。3种施肥模式下优势细菌门均为放线菌门(Actinobacteria)和变形杆菌门(Proteobacteria),优势真菌门均为子囊菌门(Ascomycota)和担子菌门(Basidiomycota)。相关性分析表明,细菌和真菌的优势菌门相对丰度与pH值和全盐含量呈负相关关系,与土壤养分中的全磷含量相关性最高。综上,施肥改变了根际土壤细菌和真菌群落的多样性,且施控释肥比施常规肥提高了饲用燕麦根际土壤微生物多样性。研究结果可为盐碱地饲用燕麦施肥模式的选择提供理论支撑。

To explore the effect of the different fertilization modes on the microbial diversity in the forage oats rhizospheric soil in saline-alkali land,we set up three fertilization modes:no fertilization,conventional fertilization and controlled-release fertilization to forage oats‘Tianyan No.1’in saline-alkali soil in this study,and 16S rRNA and ITS high-throughput sequencing were employed to investigate the bacterial and fungal diversity from rhizospheric soil,further be analyzed in the context of bioinformatics.The results showed that fertilization modes increasedαandβdiversity of the rhizospheric soil bacterial and fungal than no fertilization mode,among which the bacterial and fungal community under controlled-release fertilizer mode had the highest OTU number.The dominant bacterial phyla were mainly Actinobacteria and Proteobacteria,and the dominant fungal phyla mainly Ascomycota and Basidiomycota in three fertilization modes.Correlation analysis showed that the relative abundance of dominant bacterial and fungal phyla was negatively correlated with pH and total salt content,and was most significantly related to total phosphorus content in soil nutrients.These results concluded that fertilizer application changed the diversity of rhizosphere soil bacterial and fungal communities;notably,that controlled-release fertilizer application increased the microbial diversity of rhizospheric soil of forage oats compared with conventional fertilizer application.The results of this research could provide theoretical support for the selection of fertilization mode for forage oats in saline-alkali lands.