高寒沙化草地土壤微生物群落结构特征研究

Study on the Characteristics of Soil Microbial Community Structure in Alpine Desertification Grassland

摘要: 气候变化与人为活动引起的高寒草地退化对草地土壤生态系统产生了重要影响。迄今对高寒沙化草地土壤的物理、化学和生物学特性研究较多，而对土壤微生物特性的关注较少，特别是对沙化草地土壤微生物群落结构特征和微生物多样性分布特征的了解尚不深入。为此，本研究选择青藏高原东缘高寒沙化草地为研究对象，采用Illumina高通量测序分析技术，选择16S rRNA V3-V4区对沙化草地土壤进行测序分析，研究沙化土壤中微生物多样性和群落结构特征。结果表明：研究区供试土壤细菌有25门，54纲，99目，197科，340属，653种，1331OTUs。其中组内占比含量超过10%的优势菌门共有3个门类，其中放线菌门Actinobacteria占比最高，为29.34%。其次为变形菌门Proteobateria，占26.75%，最后为酸杆菌门Acidobacteria，占16.43%，在属水平上的优势菌属为酸杆菌属norank_c_Acidobacteria。总体而言，沙化草地土壤中微生物多样性总体不高，草地沙化过程对土壤中的微生物可能产生了抑制作用。

Abstract: Process on the alpine grassland degradation has a great effect on soil ecosystem due to the climate change and humans activities. At present, the physical, chemical and biological characteristics of the soil in the alpine desertification grassland have been studied so far, and the attention to the soil microbial characteristics is less, especially the understanding of the characteristics of the soil microbialcommunity and the distribution of the microbial diversity in the sandy grassland. In this study, alpine sandy grassland on the eastern margin of Qinghai-Xizang Plateau was selected as the research object; using Illumina high throughput sequencing technique, the 16S rRNA V3-V4 area was applied to sequence the sandy soil, and the characteristics of microbial diversity and commu-nity structure in sandy soil were studied. The results showed that there were 25 phylums, 54 classes, 99 orders, 197 families, 340 genuses, 653 species, and 1331 OTUs in the tested soil of study area. Among them, there were three dominant bacteria with more than 10% proportion, among which Actinobacteria accounted for the highest (29.34%), and the Proteobateria accounted for 26.75%; Acidobacteria represented 16.43% of the total. At the genus level, the dominant genus is norank_c__Acidobacteria. All in all, the soil microbial diversity in sandy land was low and soil desertification has an inhibitory effect on microorganisms in soil.