基于高通量测序分析西藏北部高寒草甸不同深度土壤线虫群落分布特征

为了研究藏北高寒草甸土壤线虫多样性,于2017年8月,采用Illumina MiSeq测序技术,研究了西藏北部高寒草甸0—25 cm范围内不同深度土层的土壤线虫群落组成与结构特征。结果表明:5个不同深度共获得OTU 990个,隶属于3个纲,7个目,25个科,30个属,刺嘴纲Enoplea为共有优势土壤线虫群落;对样品进行Alpha多样性评价,计算Chao 1指数、Shannon指数和Ace指数,发现5—10 cm的土壤样品群落有较高的丰富度;属水平Heatmap图分析可知20—25、15—20、0—5、5—10、10—15 cm土壤线虫群落的组成相似性有一个递增的趋势。与不同深度藏北高山嵩草(盛长期)线虫群落结构相关性较大的土壤化学指标是K~+、含水率、有机质和Zn~(2+)。研究发现不同深度土壤线虫种类及丰度存在一定的差异,可为研究藏北高寒草地土壤线虫群落特点提供依据。

Research on the characteristics of soil nematode communities in alpine meadow in northern Tibet by using high-throughput sequencing

The goal of this study was to examine the diversity of soil nematodes in the alpine meadows of northern Tibet. In August 2017, the changes in soil nematode communities at different soil depths were analyzed using high-throughput sequencing to reveal the community composition and structural characteristics. A total of 990 operational taxonomic units were extracted from five samples and were sorted into 3 classes, 7 orders, 25 families, and 30 genera. Enoplea was dominant in the different samples at the class level. The Chao1 index, Shannon index, and Ace index were used to evaluate the alpha diversity of the samples, and the results showed that the 5-10 cm soil layer had a relatively high abundance. A heatmap analysis showed the composition similarity of the community was 20-25 cm < 15-20 cm < 0-5 cm < 5-10 cm < 10-15 cm. A redundancy analysis of the soil nematode phyla and the chemical parameters in the soil showed that K⁺, soil water content, organic matter, and Zn²⁺ were the most related to the soil nematode community structure. Differences were noted in the species and abundance of soil nematodes at the different depths, which provides a basis for studying the characteristics of soil nematode communities in the alpine grasslands in northern Tibet.