Diversity of soil nitrogen-fixing microorganisms in Salicornia europaea community of Ebinur Lake wetland during different periods

Abstract:

[Objective] The primary goal of this study was to explore the correlation between the diversity and abundance of nitrogen-fixing microbes and the physicochemical factors of rhizosphere and non-rhizosphere soil types during different seasons. We aimed to explore the potential role of nitrogen-fixing microbial communities in restoring ecological functions. This study may provide the theoretical foundation and preliminary data for future studies in this field. [Methods] Illumina HiSeq PE250 sequencing technique was used to analyze the diversity of nitrogen-fixing microorganisms in six different soil samples. RDA analysis was used to explore the correlation between the physicochemical factors and the structure and abundance of nitrogen-fixing microbial communities in these soil samples.[Results] The diversity of nitrogen-fixing bacteria in rhizosphere soil was higher than that in non-rhizosphere soil. Additionally, the diversity observed in July was higher than that in October and April. Bacteria belonging to the genera Geobacter, Pseudomonas, Azotobacter and Bradyrhizobium were predominant in Salicornia europaea rhizosphere and non-rhizosphere soils. The predominant phyla of nitrogen-fixing microorganisms were Proteobacteria and Cyanobacteria, whose relative abundance accounted for 85% and 10%, respectively, while the others accounted for less than 5%. The predominant nitrogen-fixing microflora in the soil was significantly correlated with alkali-hydrolyzed nitrogen (AN), total nitrogen (TN), available potassium (AK), and total phosphorus (TP). [Conclusion] The diversity and community structure of nitrogen-fixing microorganisms in soil samples varied in different seasons. The community structure of nitrogen-fixing microorganisms was different in rhizosphere and non-rhizosphere soil types during the same period. These experimental results may provide the theoretical foundation and preliminary data for the restoration of Ebinur Lake wetland.