利用沉积物和水体的环境DNA检测鱼类物种多样性的差异

Difference in fish species diversity detected by environmental DNA from sediments and water

环境DNA(environmental DNA,eDNA)调查因其敏感且能提供高分辨率的群落组成数据,正越来越多地被用于生物多样性的监测。但环境DNA研究评估不同的环境样本类型如何影响物种的可检测性仍然很少。在此,我们利用线粒体细胞色素b基因的环境DNA宏条形码比较了鄱阳湖中沉积物和水体的鱼类群落组成。结果显示:沉积物样本注释到6目10科18种,水体样本中注释到5目7科13种。沉积物和水体环境DNA共同注释到8种鱼类(32%)。本研究注释到的鱼以鲤科鱼类居多,且以小型、湖泊定居型、杂食性鱼类为主。沉积物样本中检测到的鱼类的多样性高于水体中的。鱼类环境DNA有垂直分布差异。本研究得出结论,在进行环境DNA调查时需要仔细考虑环境样本类型。建议在使用环境DNA进行鱼类资源研究时,取样策略采取沉积物样本和水体样本相结合将会更有意义。

Environmental DNA(eDNA)surveys are increasingly used to monitor biodiversity because of their sensitivity and ability to provide high resolution community composition data.However,the studies on how different types of environmental samples affect species'detectability based on eDNA remain limited.In Poyang Lake,for the compositions of fish community in sediments and in Water,they were compared by using the eDNA macrobarcoding of the cytb gene.The results showed that the sediment samples were annotated to 18 species of 6 orders,10 families,and the water samples were annotated to 13 species of 5 orders,7 families.The eDNA in sediments and water jointly annotated 8 species(32%).The fishes annotated in this study were mostly cyprinid fish and were mainly small,lake-dwelling,and omnivorous.The diversity of fish detected in sediment samples was higher than that in water.There were differences in the vertical distribution in the eDNA of fish.It was concluded in this study that environmental sample types need to be carefully considered when conducting eDNA investigations.It is suggested that when using eDNA to study fish stocks,it would be more meaningful to combine sediment with water as sampling strategy.