Zhang Li-Juan, Xu Shan, Zhao Zheng, Zhou Xiao-Hua, Feng Qing, Yang Jiang-Hua, Li Fei-Long, Wang Zhi-Hao, Zhang Xiao-Wei
State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
Kunming Dianchi Lake Environmental Protection Collaborative Research Center, Kunming University, Kunming 650214, China.
Huan Jing Ke Xue. 2021 Feb 8;42(2):796-807. doi: 10.13227/j.hjkx.202007236.
Environmental DNA (eDNA) metabarcoding provides a fast and efficient way to obtain biodiversity information that has been widely used in aquatic biodiversity monitoring and assessment. To facilitate the application of eDNA metabarcoding in China, the accuracy of metabarcoding data needs to be further assessed. Here, the eukaryotic phytoplankton in Dianchi Lake and the northern portion of Fuxian Lake were examined. The effect of sequencing depth on species diversity was also explored, and accuracy was evaluated by comparing the taxon overlap and coefficient of variation (CV) of the diversity index among biological replicates. The results showed that:① Sequencing depth significantly affected the taxon number and accuracy of alpha diversity determinations. The suggested sequencing depth for metabarcoding of eukaryotic phytoplankton in Dianchi Lake and Fuxian Lake is at least 30000. ② The OTU overlap was 45.97%±1.67% among three biological replicates, the genera overlap was 64.21%±3.25%, and the CV of alpha diversity was less than 10%. ③ Seventy-five and 90 genera of eukaryotic algae were identified in Dianchi Lake and Fuxian Lake, respectively, covering 62.5% and 71.05% of the morphologically detected species, respectively. ④ There was no significant variation in the diversity of eukaryotic algae with depth in Dianchi Lake, while diversity showed significant vertical patterns in Fuxian Lake. Overall, eukaryotic algal diversity was significantly lower in Dianchi Lake compared to Fuxian Lake, and diversity in the southern portion of Dianchi Lake was significantly higher than that in the central and northern portions (<0.05). Our study demonstrates the feasibility and accuracy of using eDNA-based techniques to monitor eukaryotic phytoplankton diversity, which supports the widespread application of eDNA metabarcoding in China.
环境DNA（eDNA）宏条形码技术提供了一种快速有效的获取生物多样性信息的方法，已广泛应用于水生生物多样性监测与评估。为推动eDNA宏条形码技术在中国的应用，需进一步评估宏条形码数据的准确性。在此，对滇池和抚仙湖北部的真核浮游植物进行了研究。还探讨了测序深度对物种多样性的影响，并通过比较生物重复样本间分类群重叠率和多样性指数的变异系数（CV）来评估准确性。结果表明：①测序深度显著影响分类单元数量和α多样性测定的准确性。滇池和抚仙湖真核浮游植物宏条形码测序的建议深度至少为30000。②三个生物重复样本间的OTU重叠率为45.97%±1.67%，属重叠率为64.21%±3.25%，α多样性的CV小于10%。③滇池和抚仙湖分别鉴定出75个和90个真核藻类属，分别占形态学检测物种的62.5%和71.05%。④滇池真核藻类多样性随深度无显著变化，而抚仙湖多样性呈现显著的垂直分布格局。总体而言，滇池真核藻类多样性显著低于抚仙湖，滇池南部的多样性显著高于中部和北部（<0.05）。我们的研究证明了使用基于eDNA的技术监测真核浮游植物多样性的可行性和准确性，支持了eDNA宏条形码技术在中国的广泛应用。
