Journal of Integrative Agriculture ›› 2021, Vol. 20 ›› Issue (12): 3299-3311.DOI: 10.1016/S2095-3119(20)63462-1

所属专题: 农业生态环境-土壤微生物合辑Agro-ecosystem & Environment—Soil microbe

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  • 收稿日期:2020-07-20 出版日期:2021-12-01 发布日期:2021-10-20

Assembly and co-occurrence patterns of rare and abundant bacterial sub-communities in rice rhizosphere soil under short-term nitrogen deep placement

LI Gui-long1, 2, WU Meng1, 2, LI Peng-fa1, 2, WEI Shi-ping1, 2, LIU Jia1, 3, JIANG Chun-yu1, LIU Ming1, 2, LI Zhong-pei1, 2 
  

  1. 1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, P.R.China
    2 University of Chinese Academy of Sciences, Beijing 100049, P.R.China
    3 Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, P.R.China
  • Received:2020-07-20 Online:2021-12-01 Published:2021-10-20
  • Contact: Correspondence LI Zhong-pei, Tel: +86-25-86881323, E-mail: zhpli@issas.ac.cn
  • About author:LI Gui-long, Mobile: +86-13455171603, E-mail: glli@issas.ac.cn;
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (2016YFD0200309 and 2018YFD0301104-01).

摘要:

研究表明氮肥深施能够减少稻田中氮素淋失、提高氮肥利用率;然而,我们对于稻田土壤微生物,特别是微生物中的丰富物种和稀有物种对于氮肥深施的响应知之甚少,而这一过程对于我们理解农业生态系统的生物多样性和功能至关重要。在本研究中,我们利用二代测序技术和生态模型理论,研究了不同氮肥施用条件下水稻根际土壤中丰富和稀有类群在水稻生长4个阶段的多样性模式及其组装机制。结果显示,在水稻根际土壤中丰富物种和稀有物种具有不同的分布模式:丰富物种广泛存在于各样品中,而稀有物种不是普遍存在的。随机过程在丰富菌群和稀有菌群的群落构建过程中均起着主导作用,其中扩散限制在丰富菌群中起着更重要的作用,而漂移等非主导过程在稀有菌群中起着更重要的作用。扩散限制对氮肥深施下丰富物种和稀有物种的影响高于不施氮肥和传统撒施;然而均值扩散对不施氮肥和传统撒施下稀有物种的影响高于氮肥深施处理。网络分析表明,与稀有物种相比,丰富物种相互之间连接紧密且占据网络的中心位置。尽管如此,大部分的关键物种由稀有物种组成,它们可能在维系网络稳定过程中发挥重要作用。总之,我们的研究结果突出了氮肥深施下根际土壤中丰富菌群和稀有菌群生态机制和共发生模式。


Abstract:

Nitrogen (N) deep placement has been found to reduce N leaching and increase N use efficiency in paddy fields.  However, relatively little is known how bacterial consortia, especially abundant and rare taxa, respond to N deep placement, which is critical for understanding the biodiversity and function of agricultural ecosystem.  In this study, Illumina sequencing and ecological models were conducted to examine the diversity patterns and underlying assembly mechanisms of abundant and rare taxa in rice rhizosphere soil under different N fertilization regimes at four rice growth stages in paddy fields.  The results showed that abundant and rare bacteria had distinct distribution patterns in rhizosphere samples.  Abundant bacteria showed ubiquitous distribution; while rare taxa exhibited uneven distribution across all samples.  Stochastic processes dominated community assembly of both abundant and rare bacteria, with dispersal limitation playing a more vital role in abundant bacteria, and undominated processes playing a more important role in rare bacteria.  The N deep placement was associated with a greater influence of dispersal limitation than the broadcast N fertilizer (BN) and no N fertilizer (NN) treatments in abundant and rare taxa of rhizosphere soil; while greater contributions from homogenizing dispersal were observed for BN and NN in rare taxa.  Network analysis indicated that abundant taxa with closer relationships were  usually more likely to occupy the central position of the network than rare taxa.  Nevertheless, most of the keystone species were rare taxa and might have played essential roles in maintaining the network stability.  Overall, these findings highlighted that the ecological mechanisms and co-occurrence patterns of abundant and rare bacteria in rhizosphere soil under N deep placement.
 

Key words: rare bacteria ,  community assembly ,  network analysis ,  co-occurrence patterns ,  N deep placement