Different Continuous Cropping Spans Significantly Affect Microbial Community Membership and Structure in a Vanilla-Grown Soil as Revealed by Deep Pyrosequencing
Different Continuous Cropping Spans Significantly Affect Microbial Community Membership and Structure in a Vanilla-Grown Soil as Revealed by Deep Pyrosequencing
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DOI：
10.1007/s00248-014-0516-0
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发表时间：
2015-07-01
影响因子：
3.6
通讯作者：
Shen, Qirong
中科院分区：
文献类型：
--
作者：
Xiong, Wu;Zhao, Qingyun;Shen, Qirong
本研究通过16S核糖体RNA(RRNA)基因和内部转录间隔区(ITS)的深度焦磷酸测序，对香草兰连作时间序列田土壤细菌和真菌群落进行了评估。结果表明，长期单一种植香草兰显著改变了土壤微生物群落。土壤真菌多样性指数随连作年限的增加而增加，而土壤细菌多样性相对稳定。Bray-Curtis相异聚类和UniFrac加权主坐标分析(PCoA)表明，单代培养时间是真菌群落结构的主要决定因素，而不是细菌群落结构的主要决定因素。随着香草兰单一栽培年限的增加，菌丝体、放线杆菌、拟杆菌和担子菌门的相对丰度(RAS)逐渐减少。在门水平上的皮尔逊相关分析表明，放线杆菌、单胞菌、拟杆菌、韦氏杆菌和腐霉菌与香草病指数(DI)呈显著负相关，而与真菌门的相关性不显著。此外，病原菌尖孢镰刀菌的数量随着年份的增加而积累，且与香草兰的DI呈显著正相关。相比之下，包括慢生根瘤菌和芽孢杆菌在内的有益细菌的丰度随着时间的推移显著下降。综上所述，长期连作后土壤虚弱和香草兰枯萎病可归因于土壤微生物群落组成和结构的改变，即有益微生物的减少和真菌病原菌的积累。
In the present study, soil bacterial and fungal communities across vanilla continuous cropping time-series fields were assessed through deep pyrosequencing of 16S ribosomal RNA (rRNA) genes and internal transcribed spacer (ITS) regions. The results demonstrated that the long-term monoculture of vanilla significantly altered soil microbial communities. Soil fungal diversity index increased with consecutive cropping years, whereas soil bacterial diversity was relatively stable. Bray-Curtis dissimilarity cluster and UniFrac-weighted principal coordinate analysis (PCoA) revealed that monoculture time was the major determinant for fungal community structure, but not for bacterial community structure. The relative abundances (RAs) of the Firmicutes, Actinobacteria, Bacteroidetes, and Basidiomycota phyla were depleted along the years of vanilla monoculture. Pearson correlations at the phyla level demonstrated that Actinobacteria, Armatimonadetes, Bacteroidetes, Verrucomicrobia, and Firmicutes had significant negative correlations with vanilla disease index (DI), while no significant correlation for fungal phyla was observed. In addition, the amount of the pathogen Fusarium oxysporum accumulated with increasing years and was significantly positively correlated with vanilla DI. By contrast, the abundance of beneficial bacteria, including Bradyrhizobium and Bacillus, significantly decreased over time. In sum, soil weakness and vanilla stem wilt disease after long-term continuous cropping can be attributed to the alteration of the soil microbial community membership and structure, i.e., the reduction of the beneficial microbes and the accumulation of the fungal pathogen.