Author(s)

Lu Lu^1*, Huilin Li², Yan He², Jing Zhang¹, Juan Xiao¹, Chao Peng¹

¹College of Environmental Science and Engineering, China West Normal University, Nanchong, China.
²Key Laboratory of Southwest China Wildlife Resources Conservation College of Life Sciences, China West Normal University, Nanchong, China.

Soil nitrification is mediated by ammonia-oxidizing archaea (AOA) and bacteria (AOB), which occupy different specialized ecological niches. However, little is known about the diversification of AOA and AOB communities in a large geographical scale. Here, eight paddy soils collected from different geographic regions in China were selected to investigate the spatial distribution of AOA and AOB, and their potential nitrification activity (PNA). The result showed that the abundance of AOA was predominant over AOB, indicating that the rice fields favor the growth of AOA. PNA highly varied from 0.43 to 3.57 μg NO_X-N·g·dry·soil·h^-1, and was positively related with soil NH₃ content, the abundance of AOA community, and negatively related with the diversity of AOB community (P < 0.01), which indicating that AOA might be the more dominant ammonia oxidizers in the collected paddy soils. Denaturing gradient gel electrophoresis fingerprints of amoA genes revealed remarkable differences in the compositions of AOA and AOB community. Phylogenetic analyses of amoA genes showed that Nitrosospiracluster-3-like and Nitrosomonas cluster 7-like AOB extensively dominated the AOB communities, and 54d9-like AOA within the soil group 1.1b predominated in AOA communities in paddy soils. Redundancy analysis suggested that the spatial variations of AOA community structure were influenced by soil TN content (P < 0.01), while no significant correlation between AOB community structure and soil properties was found. Findings highlight that ammonia oxidizers exhibit spatial variations in complex paddy fields due to the joint influence of soil variables associated with N availability.

Paddy Soil, Ammonia-Oxidizing Microorganism, Nitrification Activity, Large Geographical Scale, Diversification

Lu, L. , Li, H. , He, Y. , Zhang, J. , Xiao, J. and Peng, C. (2018) Compositional Shifts in Ammonia-Oxidizing Microorganism Communities of Eight Geographically Different Paddy Soils —Biogeographical Distribution of Ammonia-Oxidizing Microorganisms. Agricultural Sciences, 9, 351-373. doi: 10.4236/as.2018.93025.