基于环境DNA的长江中华鲟分布特征探究

中华鲟（Acipenser sinensis）是我国长江流域的旗舰物种，在长江十年禁渔的大背景下，研究中华鲟无损化检测技术具有重要意义。环境DNA（eDNA）技术是一种环境友好型生物监测技术，可以在不直接观察或捕获生物体的情况下对物种进行检测。从文献中筛选出可以用于检测中华鲟eDNA的特异性引物，于2020年9月在长江中下游选取4个中华鲟常出现的区域，进行各断面立体式采样；提取16个点位的eDNA，使用筛选得到的引物对中华鲟进行eDNA的检测，以探究中华鲟的分布特征。结果显示，成功筛选到1组可以检测中华鲟eDNA的引物，使用该引物成功检测到包括中华鲟在内的长江4种鲟类的eDNA，共计测得约300万条鲟类序列。依据测序结果分析不同断面检测到的中华鲟eDNA的差异，发现宜昌江段断面的中华鲟eDNA最多，洞庭湖口断面最少，且表层和底层水体的中华鲟eDNA检出也有显著差异。筛选得到的引物可以用于中华鲟eDNA的检测，中华鲟eDNA的检测结果与中华鲟的历史调查和洄游特征较为吻合。不同水深条件中华鲟eDNA的检出量有显著差异，表明在今后的调查中采用混合或者立体采样可以更加全面地进行中华鲟eDNA的检测。

Distribution characteristics of Chinese sturgeon in the Yangtze River based on environmental DNA

Chinese sturgeon (Acipenser sinensis) is a flagship species in the Yangtze River basin. Under the background of the 10-year fishing ban in the Yangtze River, it is of great significance to study the nondestructive testing technology of Chinese sturgeon. Environmental DNA (eDNA) technology is an environmentally friendly biological monitoring technology, which can detect species without direct observation or capture of the organism. It was tried to screen out the specific primers that could be used to detect the eDNA of Chinese sturgeon from the literature. In September 2020, four areas where Chinese sturgeon often appeared were selected in the middle and lower reaches of the Yangtze River, and three-dimensional sampling was performed on each section. eDNA of 16 sites was extracted, and the screened primers were used to detect the eDNA of Chinese sturgeon, in order to try to explore the distribution characteristics of Chinese sturgeon. A group of primers that could detect the eDNA of Chinese sturgeon was successfully screened. By using this primer, the eDNA of 4 species of sturgeon in the Yangtze River including the Chinese sturgeon was successfully detected, and about 3 million sequences of sturgeon were measured. Based on the sequencing results, the differences in the eDNA of Chinese sturgeon detected in different sections were analyzed. It was found that the eDNA in Yichang River section was the most, and the eDNA in Dongting Lake mouth section was the least, and there were significant differences in the eDNA detection between the surface and bottom waters. The study found that the screened primers could be used for the detection of eDNA of Chinese sturgeon, and the detection results of eDNA were consistent with the historical investigation and migration characteristics of Chinese sturgeon. There were significant differences in the amount of Chinese sturgeon eDNA detected under different water depths, which indicated that mixed or three-dimensional sampling may be more comprehensive for the detection of Chinese sturgeon eDNA in the future investigation.