Biology and Fertility of Soils：新鲜土壤与风干土壤中的氨氧化菌群落变化...

中国科学院南京土壤所贾仲君研究员团队测定了22年间不施肥、施用化肥、化肥/有机肥配施的新鲜土壤和风干土壤中氨氧化细菌和氨氧化古菌群落的丰度和组成。相关成果发表于Biology and Fertility of Soils（IF=3.808）。

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Abstract

In this study, we show that composition shifts of ammonia oxidizer communities imposed by a 22-year field fertilization regime could be well retained in both fresh and air-dried soils. The abundance and composition of ammonia-oxidizing bacteria (AOB) and archaea (AOA) were measured in fresh soils, which received no fertilization (CK), chemical fertilization (NPK), and chemical plus organic matter fertilization (NPK/OM) for 22 years. The air-drying treatment of fresh soil was also conducted for pairwise analysis. We found that in fresh soils DGGE fingerprints of AOB showed significant changes under both NPK and NPK/OM treatments when compared with control (CK) and that microbial shift was almost identical in air-dried soils. Long-term nutrient fertilization did not affect AOA communities in either air-dried or fresh soils. Compared to CK treatment, real-time PCR indicated that AOB amoA genes increased significantly in fresh soils of NPK (59-fold) and NPK/OM (48-fold) plots and in air-dried NPK and NPK/OM soils by 22-fold and 19-fold respectively. Our results demonstrate that community shifts of AOB in fresh soils under chronic N fertilization could be well preserved in air-dried soils, despite the apparent decline in absolute abundance of ammonia oxidizers. These results suggest that air-dried soil could be a useful resource for deciphering the adaptive strategy of ammonia oxidizers under N enrichment when the significant changes of community composition occurred in fresh soils.

本研究发现，在持续22年的田间施肥处理下，氨氧化菌群落的组成在新鲜和风干土壤中有一致的变化。研究测定了22年间不施肥（CK）、施用化肥（NPK）、化肥/有机肥配施（NPK/OM）的新鲜土壤和风干土壤中氨氧化细菌（AOB）和氨氧化古菌（AOA）群落的丰度和组成。对新鲜土壤进行了风干处理，并进行成对分析，发现在新鲜土壤中，与CK处理相比，在NPK和NPK/OM处理下，AOB群落的DGGE指纹图谱均有显著变化，风干土壤微生物群落变化与新鲜土壤几乎相同。长期施肥对风干土壤和新鲜土壤中的AOA群落均无明显影响。实时PCR结果表明，与CK处理相比，新鲜土壤中AOB群落的amoA基因在NPK处理（59倍）和NPK/OM处理（48倍）下均有显著增长，在风干土壤中也有相同变化趋势，分别增加为22倍和19倍。实验结果表明，尽管氨氧化菌群落的绝对丰度明显下降，但在长期施用氮肥条件下，新鲜土壤中氨氧化菌群落变化在风干土壤中仍能较好地保存。这些结果表明，在新鲜土壤群落组成发生显著变化的情况下，风干土壤可以作为一种解释施氮肥条件下氨氧化菌适应性策略的有效来源。