【作者】 杨计平； 李跃飞； 朱书礼； 陈蔚涛； 薛慧敏； 李新辉；

【Author】 YANG Jiping;LI Yuefei;ZHU Shuli;CHEN Weitao;XUE Huimin;LI Xinhui;Pearl River Fisheries Research Institute, Chinese Academy of fishery science, Scientific Observing and Experimental Station of Fishery Resources and Environment in the Middle and Lower Reaches of Pearl River,Ministry of Agriculture;College of Marine Sciences Shanghai Ocean University;

【机构】 中国水产科学研究院珠江水产研究所农业部珠江中下游渔业资源环境科学观察实验站； 上海海洋大学海洋科学学院；

【摘要】 鳤(Ochetobius elongatus)曾经是我国许多河流的重要经济鱼类,然而由于环境污染和人为干扰等原因,鳤的资源量萎缩严重,种群处于极度濒危的境地。目前,常规采样方法获得鳤样本的难度较大,致使相关研究难以开展。本研究通过简化基因组测序(RAD)技术开发鳤的微卫星标记,对采集的鳤仔鱼和成鱼样本进行遗传多样性分析。结果显示,共获得鳤微卫星(SSR)标记数25716个,在随机挑选的120个SSR标记中,28个标记呈现重复性好、多态性高的特征。遗传多样性分析发现,鳤的观测杂合度Ho和期望杂合度He分别介于0.33-0.96和0.387-0.853之间,多态信息含量指数(PIC)为0.378-0.836,平均为0.648(>0.5),表明西江中下游鳤的遗传多样性处于中等较高的水平。主坐标分析和群体分层结果均表明肇庆江段2011和2013年的鳤鱼苗均未发生遗传分化,且遗传分化系数FST为0.00363(p=0.28829±0.0424)。作为鳤可能的重要产卵场,西江中下游部分江段可以考虑建立鳤的自然保护区,用于保育和修复鳤的种质资源。更多还原

【Abstract】 Ochetobius elongatus was once an economically valuable fish species in numbers of rivers in China. Nevertheless, the resources of this species reduce rapidly and its populations are in a critically endangered condition because of environmental destruction and human disturbance. To date, it is pretty difficult to obtain O. elongatus, which limits the correlational studies on this species. We obtained O. elongatus via larva fish collection and adult fish collection. Restriction site-associated DNA sequencing(RAD-seq) were employed to develop microsatellite markers of O. elongatus in middle and lower Xijiang River. The results showed that 25716 SSRs were yielded, from which we randomly selected 120 SSRs to validate and characterize polymorphism by STR genotyping, Among the 120 SSRs, 28 polymorphic SSRs markers were screened and used to population genetic analysis. The results revealed that the observed and expected heterozygosity ranged from 0.330 to 0.960 and from 0.387 to 0.853, respectively, and the value of polymorphism information content(PIC) ranged from 0.378 to 0.836(mean 0.648, PIC>0.5), suggesting a high level of genetic diversity of O. elongatus in middle and lower Xijiang River. Additionally, Principal Coordinate Analysis(PCoA) and population simulation analysis based on an individual’s genetic composition demonstrated that no Genetic differentiation exist between 2011 and 2013 larval O. elongates, Besides, The genetic differentiation coefficient Fst between the two populations also confirmed this result(p=0.28829±0.0424). As a potentially important spawning ground for O. elongatus, some sections in middle and lower Xijiang River can be established some nature reserves to conserve and restore its genetic resources.更多还原