摘要:土壤微生物对土壤肥力的形成和植物营养的转化起着积极的作用。对盐渍化土壤中植物根际微生物群落组成和多样性进行研究，有助于发现新的重要微生物功能类群或者功能潜力，对于盐碱土壤的植被恢复和生态重建都具有十分重要的意义。通过高通量测序和分离培养方法，对宁夏银北地区盐渍化土壤中的6种耐盐植物根际细菌的群落结构和多样性进行了分析。结果表明：所有土壤样品共检测到31门（亚门） 67纲253科400属细菌类群，不同植物根际微生物群落组成相似，但丰度各有差异，厚壁菌门、变形菌门、放线菌门和拟杆菌门为主要优势类群；在纲水平芽孢杆菌纲相对丰度最高，其次为α-变形菌、γ-变形菌和梭菌纲；在属水平上，芽孢杆菌属以极高的丰度（15.57%-53.85%）占据绝对优势，其次是鞘氨醇单胞菌属、不动杆菌属和节杆菌属。6种植物根际细菌的群落结构组成表现为芨芨草和柽柳相似，柳枝稷、苜蓿与枸杞相似，苦豆子则与另外5种差别最大。分离培养出的110株根际细菌多数具有较强的盐碱耐受性和一种以上生物学活性，分别隶属于芽孢杆菌属、假单胞菌属、鞘氨醇杆菌属、节杆菌属和中华根瘤菌属，在属水平上多样性单一，其中芽孢杆菌属是优势属。传统的分离培养和高通量测序结果都反映出银北地区盐渍化土壤中定殖着许多有重要生态功能的微生物类群，可用于进一步筛选和利用根际微生物改良盐碱土壤。



Abstract:Soil microbes play a positive role in the formation of soil fertility and the transformation of plant nutrients. Studying the composition and diversity of rhizosphere bacteria communities in salinized soils can help to elucidate new important microbial functional groups or functional potentials, which are of great significance for vegetation restoration and ecological reconstruction of saline-alkaline soils. In this study, the rhizobacteria communities and diversity of six plants in saline soils in the Yinbei area of Ningxia were analyzed by high-throughput sequencing technology and culture methods. The results showed that a total of 31 phyla, 67 classes, 253 families, and 400 genera were detected in all soil samples. The bacterial community composition in different plant rhizospheres were similar, but the relative abundance was different. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the dominant phyla. At the class level, the relative abundance of Bacilli was the highest, followed by α-proteobacteria, γ-proteobacteria, and Clostridia. Bacillus was the dominant genus with an extremely high abundance (15.57%-53.85%), followed by Sphingomonas, Acinetobacter, and Arthrobacter. The community structure of the rhizosphere bacteria of the 6 plants showed: That of Achnatherum splendens and Tamarix chinensis were similar; those of Panicum virgatum, Medicago sativa, and Lycium barbarum were similar, and that of Sophora alopecuroides was the most different from the other 5 plants. Most of the 110 isolated strains had strong salt-tolerance and more than one biological activity, belonging to the genera Bacillus, Pseudomonas, Sphingobacterium, Arthrobacter, and Sinorhizobium. The diversity at the genus level was poor, and Bacillus was the dominant genus. The results of the traditional culture method and high throughput sequencing technology all reflected that many important ecological functional microorganisms were colonized in the Yinbei saline-alkali area, which could be further screened and utilized to improve saline soil.





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