鄱阳湖及洞庭湖红鳍原鲌的群体分化研究

摘要

To investigate population differentiation of Cultrichthys erythropterus, 186 samples were collected from 6 localities in Poyang Lake (HK, XZ, DC, PY, YG) and Dongting Lake (DTH) to analyze the morphology and Cyt b se-quence. The results showed that there were no significantly morphological differences among populations. The genetic differentiation coefficient (Fst) ranged from–0.00567 to 0.33429, indicating evidently genetic differences among popu-lations that further supported by the analysis of haplotype distributions and ANOMA. The NJ tree of the six populations revealed that the XZ, DC, PY and YG population had the closest relationship that was clustered to form one branch, and DTH population was clustered to all other populations for another branch except HK that is the transitional population between these two branches. Perhaps, C. erythropterus was the lacustrine fishes, which resulted in long-term isolated history and limited gene flow.%结合形态和线粒体 Cyt b 数据,研究了鄱阳湖及洞庭湖定居性鱼类鲌红鳍原的6个地理群体(湖口群体、星子群体、都昌群体、鄱阳群体、余干群体和洞庭湖群体)共186尾样本的群体分化情况。形态分析结果显示地理群体间形态差异较小。遗传分析结果中,群体间遗传分化指数(Fst)为–0.00567—0.33429,显示群体间存在较大遗传差异,而单倍型分布和分子变异分析(AMOVA)也得到相似的结果。根据群体遗传距离构建的系统树,6个群体分为两大支：洞庭湖群体与其他群体距离最远,单独聚为一支；星子、都昌、鄱阳和余干4群体聚成另一支,而湖口群体处于两支的过渡位置。因此,群体间已产生显著遗传分化,且主要体现在鲌洞庭湖和鄱阳湖各群体间。综合上述分析结果及红鳍原的生活习性认为,鲌鄱阳湖及洞庭湖红鳍原群体间鲌的遗传分化是红鳍原定居性的生活习性导致不同地理群体间长期的群体隔离、缺乏基因交流的结果。