不同施肥处理对我国紫色土丘陵区坡耕地土壤中致病菌组成的影响

Effect of Different Fertilization Treatments on Composition of Pathogenic Bacterium in Hilly Cropland of Purple Soil in Sichuan

施用有机肥增加土壤肥力的同时,导致致病菌在土壤中富集,使土壤成为致病菌传播的主要媒介。以不施肥、单施猪粪、猪粪与氮肥混施和猪粪与氮、磷、钾肥混施这4种处理进行为期13 a的施肥试验,采用高通量测序技术探讨各个施肥处理土壤中致病菌组成和影响因素。结果表明,土壤样品中共检出18个致病菌属,对照组中致病菌属的检出率为27.78%~33.33%,与之相比,在有机肥处理中致病菌属的检出率处在较高水平,为38.89%~55.56%;耻垢分枝杆菌Mycobacterium smegmaits、魏登施泰滕芽孢杆菌Bacillus weihenstephanensis和巨大芽孢杆菌Bacillus megaterium为紫色土丘陵区坡耕地土壤中最为普遍的致病菌,占总丰度的45.5%~80.0%,其中耻垢分枝杆菌在所有样品中均有检出。主坐标分析和单因素方差分析结果表明,不同施肥处理土壤中致病菌的组成和相对丰度没有显著差异。普氏分析和冗余分析结果表明,土壤理化性质可能是紫色土丘陵区坡耕地土壤中致病菌组成的重要影响因子。综上所述,本研究为长期施用猪粪的紫色土丘陵区坡耕地土壤中致病菌的组成及影响因素提供理论依据。

In September 2016,surface soils were collected in sample plots applied with no fertilizer(CK),pig manure alone,pig manure mixed with nitrogen fertilizer and pig manure mixed with nitrogen,phosphorus and potassium fertilizers for 13 years in Yanting Purple Soil Station of Agricultural Ecological Experiment in Sichuan province. Determinations on pathogenic bacterum were implemented by high-throughput sequencing.The results demonstrated that there were a total of 18 genera in the soil samples. Mycobacterium shamefaciens,Bacillus weidenstetten and Bacillus megaterium were the most prevalent,accounting for 45.5%-80.0% of the total abundance. M. shamefaciens could be detected in every sample. The results of principal co-ordinates analysis and one-way analysis showed that there were no significant differences of composition and abundance of pathogenic bacterium among plots with different fertilization treatments. The results of procrustes analysis and redundancy analyses indicated that soil physicochemical properties might be the important influencing factor for the composition of soil pathogenic bacterium.