DNA复合条形码在太白山土壤动物多样性研究中的应用

DNA复合条形码技术(metabarcoding)将DNA条形码与高通量测序技术相结合,快速便捷地鉴定群落混合样本中的物种,成为监测群落中物种组成和丰富度的可靠方法。采用这一方法分析了秦岭太白山5种不同生境的中小型土壤动物多样性,共得到土壤动物3门9纲28目199科。群落组成分析显示生境的变化对土壤动物群落组成有一定的影响。α多样性分析显示土壤动物群落丰富度指数最高的生境为针叶林,最低的为农田;土壤动物群落多样性指数最高的生境为针叶林,最低的为落叶小叶林。群落相似性分析显示高山草甸、针叶林和农田3种生境的土壤动物群落组成相似性较高,落叶小叶林和落叶阔叶林的土壤动物群落组成与这3种生境的差异较大,落叶小叶林与落叶阔叶林的土壤动物群落组成差异也较大。

The application of DNA metabarcoding in the study of soil animal diversity in Taibai Mountain

DNA metabarcoding which couples DNA barcoding with high-throughput sequencing technology enables quick and easy identification of species in a multiple sample, and has become a reliable method for surveying species composition and richness of a community. Taibai Mountain is the main peak of the Qinling Mountains. It is a well-preserved natural ecological system, and is a key area of biodiversity protection in China. Surveys on the diversity of soil meso-microanimals in Taibai Mountain will enrich the data of soil fauna composition and provide scientific basis for biodiversity protection in China. In this paper, we used the metabarcoding approach to analyze the diversity of soil meso-microanimals in 5 different habitats of Taibai Mountain in the Qinling Mountains. These habitats include alpine meadow, coniferous forest, deciduous small-leaved forest, deciduous broad-leaved forest, and farmland. We set 3 plots of 10 m×10 m in each habitat, and 3 soil samples were collected randomly from each plot, the sampling depth was 0-15cm under ground. A Tullgren funnel was used to separate soil animals from soil samples. Soil animals from the same plot were transferred to 1.5-mL centrifuge tubes and the total DNA was extracted. The universal primers for the fraction of 18S rRNA and COI genes were used to amplify specific barcoding sequences. Sequencing of PCR amplicons was performed on a MiSeq Illumina sequencing platform. Raw data was analyzed using the Qiime and Mothur software to obtain the OTUs list and species list. Ecological analysis was performed using software R. A total of 199 families from 28 orders, 9 classes, and 3 phyla for soil animals were observed. Community composition analysis showed that habitat changes have some effect on the soil animal community composition. Alpha diversity analysis showed that the highest community richness index for soil animals is the coniferous forest and the lowest is the farmland; in addition, the highest community diversity index for soil animals is the coniferous forest and the lowest is the deciduous small-leaved forest. The community similarity analysis showed that the soil animal community composition in alpine meadow, coniferous forest, and farmland has a high similarity. The soil animal community composition in deciduous small-leaved forest and deciduous broad-leaved forest greatly differed from that in alpine meadow, coniferous forest, and farmland. The difference between the soil animal community composition in deciduous small-leaved forest and deciduous broad-leaved forest also differed greatly. The results of cluster analysis was in conformity with the community similarity analysis.