不同连作年限菠萝园土壤差异代谢物和细菌群落结构分析

Analysis of Differential Metabolites and Bacterial Community Structure in Soils of a Pineapple Orchard in Different Continuous-cropping Years

为探讨菠萝连作对土壤代谢物和细菌群落结构的影响,本研究采用非靶向代谢组学和细菌16S高通量测序技术,以菠萝园边角地未耕作过的土壤为对照(T0),对连续种植了5 a(T5)和15 a(T15)菠萝的土壤进行了代谢物与细菌群落差异比较分析。研究结果表明,与T0比较,T5和T15土壤中分别检测到120种和80种差异代谢物;T0-T5和T0-T15组间共筛选出11种具有显著性差异(VIP>1,P<0.05)的代谢物,包括有机酸4种,糖类3种,氨基酸及其衍生物2种,醇类2种;KEGG代谢通路分析表明差异代谢物主要富集在不饱和脂肪酸的生物合成途径等11条关键代谢通路中。细菌16S高通量测序结果表明,与T0相比,T5中土壤细菌群落多样性、丰富度指数均升高;T15中土壤细菌群落多样性指数升高,但丰富度指数下降。T5和T15的土壤细菌群落结构存在明显差异,在门、属水平上T5和T15土壤细菌群落的相对丰度明显高于T0。与T0相比,菠萝园土壤的两个优势菌群变形细菌门(Proteobacteria)和酸杆菌门(Acidobacteriota)在T5中所占比例升高,但在T15中所占比例下降。CCA分析结果表明,土壤pH与连作年限呈负相关。本结果可为菠萝连作对土壤环境的影响相关研究提供参考,对提高菠萝园土壤管理水平有指导意义。

In order to investigate the effects of continuous-cropping pineapple on the soil metabolites and bacteria community structure,taking the soil of uncultivated land(T0)on the edge of the orchard as the control,untargeted metabolomics and bacterial 16S high-throughput sequencing were combined to compare and analyze the metabolites of the soils continuous-cropping pineapple for 5(T5)and 15(T15)years respectively as well as differences in bacterial community.The results of metabolites analysis indicated that there were totally 120 and 80 differential metabolites in the soil of T5 and T15 when compared with T0.And 11 significantly different metabolites(VIP>1,P<0.05)were detected between T0-T5 group and T0-T15 group in total,including 4 organic acids,3 carbohydrates,2 amino acid derivatives,2 alcohols.KEGG metabolic pathways analysis suggested that the differential metabolites were mostly enriched in 11 key metabolic pathways,e.g.,biosynthesis of unsaturated fatty acids.The bacterial 16S high-throughput sequencing profiling indicated that the bacteria diversity and abundance of the soil in T5 increased when compared with T0.The bacteria diversity increased while the abundance decreased in T15 soil when compared with T0.And there were significant differences in bacterial community structure between T5 and T15.In the levels of phyla and genus,the relative abundances of soil bacteria in T5 and T15 were significantly higher than that in T0.The proportion of two dominant bacteria communities in the soil of the pineapple orchard,Proteobacteria and Acidobacteriota,increased in T5 but decreased in T15 when compared with T0.CCA analysis showed that ccontinuous-cropping years were in significantly negative correlation with pH.This work would contribute to provide a reference for related research on the impacts of ccontinuous-cropping pineapple on the soil environment and contribute to provide the guidance for improving soil management level of pineapple orchard.