Ji Wei, Zhang Gui-Rong, Ran Wei, Gardner Jonathan P A, Wei Kai-Jian, Wang Wei-Min, Zou Gui-Wei
Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, P. R. China; Freshwater Aquaculture Collaborative Innovation Centre of Hubei Province, Wuhan, P. R. China.
Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, P. R. China.
PLoS One. 2014 Sep 29;9(9):e108967. doi: 10.1371/journal.pone.0108967. eCollection 2014.
The blunt snout bream (Megalobrama amblycephala) is an important freshwater aquaculture fish throughout China. Because of widespread introductions of this species to many regions, the genetic diversity of wild and natural populations is now threatened. In the present study, SRAP (sequence-related amplified polymorphism) markers were used to assess genetic diversity of blunt snout bream. Three natural populations (Liangzi Lake, Poyang Lake and Yuni Lake, one cultured population (Nanxian) and one genetic strain ('Pujiang No. 1') of blunt snout bream were screened with 88 SRAP primer combinations, of which 13 primer pairs produced stable and reproducible amplification patterns. In total, 172 bands were produced, of which 132 bands were polymorphic. Nei's gene diversity (h) and Shannon's information index (I) values provided evidence of differences in genetic diversity among the five populations (Poyang Lake>Liangzi Lake>Nanxian>'Pujiang No. 1'>Yuni Lake). Based on cluster analysis conducted on genetic distance values, the five blunt snout bream populations were divided into three groups, Poyang Lake and Liangzi Lake (natural populations), Nanxian and 'Pujiang No. 1' (cultured population and genetically selected strain), and Yuni Lake (natural population). Significant genetic differentiation was found among the five populations using analysis of molecular variance (AMOVA), with more genetic divergence existing among populations (55.49%), than within populations (44.51%). This molecular marker technique is a simple and efficient method to quantify genetic diversity within and among fish populations, and is employed here to help manage and conserve germplasm variability of blunt snout bream and to support the ongoing selective breeding programme for this fish.
团头鲂（Megalobrama amblycephala）是中国重要的淡水养殖鱼类。由于该物种被广泛引入许多地区，野生和自然种群的遗传多样性目前受到威胁。在本研究中，利用相关序列扩增多态性（SRAP）标记评估团头鲂的遗传多样性。用88对SRAP引物组合对团头鲂的三个自然种群（梁子湖、鄱阳湖和滆湖）、一个养殖种群（南县）和一个遗传品系（“浦江1号”）进行筛选，其中13对引物产生稳定且可重复的扩增图谱。共产生172条带，其中132条带具有多态性。Nei氏基因多样性（h）和香农信息指数（I）值表明五个种群的遗传多样性存在差异（鄱阳湖>梁子湖>南县>“浦江1号”>滆湖）。基于遗传距离值进行聚类分析，五个团头鲂种群分为三组，鄱阳湖和梁子湖（自然种群）、南县和“浦江1号”（养殖种群和遗传选育品系）以及滆湖（自然种群）。利用分子方差分析（AMOVA）发现五个种群之间存在显著的遗传分化，种群间的遗传差异（55.49%）大于种群内的遗传差异（44.51%）。这种分子标记技术是一种简单有效的方法，可用于量化鱼类种群内和种群间的遗传多样性，本文采用该技术有助于管理和保护团头鲂的种质变异性，并支持正在进行的该鱼类的选育计划。
