基于高通量测序的黄河三角洲4种人工林土壤细菌结构及多样性研究

Bacterial structure and diversity of four plantations in the Yellow River Delta by high-throughput sequencing

为研究黄河三角洲不同人工林土壤细菌群落特征,应用高通量测序技术,比较分析了刺槐、榆树、白蜡、臭椿4种人工林土壤细菌结构及多样性,并结合土壤理化性质进行相关性分析。结果表明:人工林土壤中共有31门细菌;4种人工林土壤中酸杆菌门、变形菌门、放线菌门细菌以及刺槐、臭椿人工林土壤中硝化螺旋菌门细菌是土壤中的优势群落。不同人工林土壤中酸杆菌门、变形菌门、硝化螺旋菌门、芽单胞菌门、拟杆菌门、广古菌门、泉古菌门、蓝藻菌门细菌丰度差异显著。刺槐人工林土壤细菌多样性最高;白蜡人工林土壤细菌多样性最低。土壤pH、含水量、有机质含量与酸杆菌门细菌丰度呈显著负相关关系,土壤pH与变形菌门、硝化螺旋菌门、芽单胞菌门细菌丰度呈极显著正相关关系;土壤pH、有效磷含量与人工林细菌多样性呈显著正相关关系。以上研究结果表明,黄河三角洲不同人工林土壤细菌群落存在一定差异,土壤pH、含水量、有机质、有效磷含量是影响土壤细菌结构和多样性的主要土壤因素。

The Yellow River Delta, one of the three major pedogenic river deltas in China, is the fastest forming delta with important reserved land resources. To improve the environments of the Yellow River Delta, many plantations have been established since 1950s. Building plantations has been a main trend in the Yellow River Delta for it can not only adjust the temperature and relative humidity of woodlands, but also improve soil fertility. Soil provides nutrients for aboveground vegetation as well as microorganisms in soil. Soil bacteria, one of the key groups of soil microorganisms, play an important role in promoting organic matter decomposition, accelerating mineral and nutrient cycling, maintaining and improving soil fertility. By analyzing the relationship between the soil bacterial community and soil characteristics of plantations, We can understand bacteria in soil better and develop a method to improve plantations. High-throughput sequencing technology, a new method with more advantages over traditional methods to retrieves classification information of soil bacteria more conveniently and accurately, has been widely used in studying soil bacterial community now. The aim of this research was to investigate structure and diversity of the soil bacterial community at four plantations in the Yellow River Delta. Using high-throughput sequencing technology, we compared the soil bacterial structure and diversity of Robinia pseudoacacia, Ulmus pumila, Fraxinus velutina, and Ailanthus altissima plantations and analysed bacterial community correlation with its soil properties. The results showed that the bacterial community in soil of the four plantations consisted of 36 phyla. Acidobacteria, Proteobacteria, and Actinobacteria were the abundant bacterial taxa in soil of four plantations and Nitrospirae in soil of Robinia pseudoacacia and Ailanthus altissimais plantation, with their relative abundance more than 10%. There were significant differences of the relative abundance of Acidobacteria, Proteobacteria, Nitrospirae, Gemmatimonadetes, Bacteroidetes, Euryarchaeota, Crenarchaeota, Cyanobacteria in the soil among different plantations. The bacterial diversity of the Robinia pseudoacacia plantation was the highest among the four plantations sampled, with species, Chao1 index, and Shannon index being 1769.55, 2526.61, and 8.75 respectively. The bacterial diversity of the Fraxinus velutina plantation was the lowest among the four plantations, with species, Chao1 index, Shannon index being 1571.47, 1824.20, and 8.35 respectively. Water content, available K, available N, organic matter content of the Ailanthus altissima plantation and available P content of the Robinia pseudoacacia plantation were the highest among the four plantations. Available P, available K, available N, organic matter content of the Ulmus pumila plantation were the lowest. Correlation analysis showed that there was a significant negative correlation between pH, water content, organic matte content, and relative abundance of Acidobacteria, and a positive correlation between pH and relative abundance of Proteobacteria, Nitrospirae, Gemmatimonadetes. There was a significant positive correlation between pH, available P content, and bacterial diversity. The analysis of bacterial 16S rRNA showed a certain extent of differences in soil bacterial community structure and diversity of four plantations in the Yellow River Delta. Soil pH, water content, organic matter content, and available P content were the main soil factors affecting the soil bacterial structure and diversity. Further research also is needed to obtain more information about soil microorganisms.