基于微卫星标记的中华鲟亲子关系判别及案例分析

中华鲟（Acipenser sinensis）是一种大型溯河产卵洄游性鱼类。历史产卵场分布于长江上游，距离长江口2500-3000公里。1981年葛洲坝工程阻断了中华鲟洄游通道，随后天然种群数量急剧减少。人工繁殖放流补充工作从1983年开始。由于野生和人工繁殖中华鲟幼鱼有相似的洄游入海特征，因此通过在长江口水域捕获滞留的中华鲟幼鱼并区分人工繁殖个体和野生个体，可以评估中华鲟人工繁殖放流效果。本研究构建了基于四倍体遗传的微卫星标记的亲子鉴定方法，并用全同胞家系、半同胞家系和非亲缘关系群体样本验证本方法的有效性；最后将该方法用于1999年度中华鲟人工繁殖效果评估案例中，评估人工繁殖个体在长江口中华鲟幼鲟群体中的比例。亲子鉴定方法结果显示，三个全同胞家系个体间的平均遗传距离分别为0.43、0.44和0.44；半同胞家系的遗传距离居中（0.57）；长江口中华鲟幼鲟群体间的平均遗传距离是0.74。人工繁殖效果评估结果显示：在2000年度长江口幼鱼群体中，人工繁殖个体的比例较低（0～3.8％），中华鲟补充群体主要来源于自然繁殖，人工繁殖放流个体对中华鲟野生群体增殖作用不明显。

Parentage Identification and Case Analysis of Chinese Sturgeon (Acipenser sinensis) Populations Based on Microsatellite Markers

Chinese sturgeon Acipenser sinensis is an anadromous fish. Its historical spawning habitat ground was 2500- 3000 km far from the Yangtze River estuary in China. The construction of the Gezhouba Dam in 1981 blocked the migration passage and the wild population went through a drastic decline. The artificial-propagated juveniles have been released annually into the Yangtze River for stock enhancement from 1983. The wild and the artificial-propagated juveniles have the same migration characters and arrived at the estuary of the Yangtze River in next March or April. This provided a way to evaluate the percentage of the artificial individuals to the natural juveniles population in the estuary of the Yangtze River. In this study, we constructed the paternity testing method based on the tetrasomic Mendelian inheritance microsatellite markers, and then apply this method to evaluate of the percentage of released artificial individuals to the natural Chinese sturgeon population. The paternity testing method showed that the average genetic distance of the three full sibling families was 0.43, 0.44 and 0.44, respectively. The genetic distance of half-sib family is relatively middle (0.57). The distance among the juveniles in the estuary was 0.74. The results also showed a low proportion (0~3.8%) of artificially propagated individuals among juveniles in the estuary of the Yangtze River in 2000. This indicated that most of juveniles in estuary were from natural propagation.