任豆根际土壤微生物群落结构及多样性的季节变化

Seasonal Dynamics of Microbial Community Structure and Diversity in the Rhizosphere Soil of <i>Zenia insignis</i> Chun

为了说明不同植被对桂西北岩溶地区土壤质量变化的影响,以中国特有植物任豆人工林为研究对象,采集其根际土壤样品,用Illumina MiSeq高通量测序技术,分析其根际土壤细菌群落组成和物种多样性特征,测定其土壤基本理化特性和蔗糖酶、脲酶、过氧化氢酶及碱性磷酸酶活性,并对其根际土壤微生物多样性与土壤理化特性的相关性进行分析。结果表明:1) 受不同季节大气温度、降雨量、植物生长发育及土壤理化特性等因子的影响,桂西北岩溶地区任豆根际土壤养分具有较明显的季节差异,土壤微生物群落结构及物种多样性也有相应的动态变化,两者具有一定的内在联系和相关性。2) 任豆根际土壤细菌群落结构、物种丰富度及多样性有比较明显的季节差异。3) 在不同层次的细菌分类水平上,不同季节任豆根际土壤细菌群落结构相似,但优势种群的相对丰度有差异。在门水平上,秋冬季与春夏季任豆根际土壤细菌的优势菌门均为放线菌门、变形菌门、酸杆菌门、绿弯菌门,但两者丰度存在一定的差异,后者的稀有菌门相对丰度比前者更高;与秋冬季相比,在门以下的各个水平,春夏季任豆根际土壤细菌的群落结构更加复杂,特有种数量更多,丰富度更高。由此可见,不同季节任豆根际土壤细菌群落结构及多样性有较明显的变化,春夏季任豆根际土壤微生物群落结构比秋冬季复杂,其物种多样性也高于秋冬季。

In order to illustrate the effect of different vegetation on soil quality changes in the karst area of northwest Guangxi, the rhizosphere soil samples were collected from the endemic plant Z. insignis plantation in China, and the bacterial community in the rhizosphere soil was analyzed by Illumina MiSeq high-throughput sequencing technology. The composition and species diversity characteristics of the soil were determined, and the basic physical and chemical properties of the soil and the activities of invertase, urease, catalase and alkaline phosphatase were determined, and the correlation between the microbial diversity of the rhizosphere soil and the soil physical and chemical properties was analyzed. The results show that: 1) Affected by factors such as atmospheric temperature, rainfall, plant growth and development, and soil physical and chemical properties in different seasons, the rhizosphere soil nutrients of Z. insignis in the karst area of northwest Guangxi have obvious seasonal differences, soil microbial community structure and species diversity also have corresponding dynamic changes, and the two have a certain internal connection and correlation. 2) There were obvious seasonal differences in the bacterial community structure, species richness and diversity in the rhizosphere soil of Z. insignis. 3) At different levels of bacterial taxonomy, the rhi-zosphere soil bacterial community structure of Z. insignis in different seasons was similar, but the relative abundance of the dominant populations was different. At the phylum level, the dominant bacterial phyla in the rhizosphere soil bacteria of Z. insignis in autumn and winter and spring and summer are Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexbacteria, but there are certain differences in abundance of the latter. The relative abundance of rare bacteria is higher than the former. Compared with autumn and winter, at all levels below the phylum, the community structure of rhizosphere soil bacteria in the Z. insignis in spring and summer was more complex, with more endemic species and higher abundance. It can be seen that there are obvious changes in the bacterial community structure and diversity in the rhizosphere soil of Z. insignis in different seasons. The microbial community structure of the rhizosphere soil of Z. insignis in spring and summer is more complex than that in autumn and winter, and its species diversity is also higher than that in autumn and winter.