红鳍笛鲷放流苗种的遗传质量监测

Genetic quality monitoring of crimson snapper fingerlings for stock enhancement

目前中国的放流苗种遗传质量监测方法尚未建立,导致放流项目在苗种筛选过程中普遍未考查苗种的遗传质量。随着放流规模和范围的扩大,这一盲点将对放流海域的自然种群产生日益严重的遗传威胁。为逐步建立放流苗种遗传质量监测方法,该研究从遗传分歧度、遗传多样性水平、近交程度、遗传信息保持能力4个方面对比了红鳍笛鲷(Lutjanus erythopterus)放流苗种群体与自然群体,对其遗传质量进行了分析。结果表明,两群体间存在微弱遗传分歧(F_(ST)=0.016 1);放流苗种群体的遗传多样性水平和有效种群大小低于自然群体,而其近交系数均值与F_(IS)大于自然群体。上述比较证明,该苗种的遗传多样性素质低于自然群体,在遗传质量方面不能满足增殖放流要求,如果将此苗种进行放流可能产生多种负面遗传影响。从各指标偏差率看,有效种群大小的偏差率最高(-35.34%)是该苗种最突出的遗传质量缺陷。

In present, genetic quality monitoring method of hatchery-reared fingerlings for stock enhancement has not been established in China, which leads to neglection of genetic quality of fry in screening process of releasing project. With the expansion of scale of releasing, this blind spot is genetically threating to natural populations day by day. In order to establish the method, we compared the fingerlings of a Lutjanus erythopterus stock and an L. erythopterus natural stock from four aspects （ genetic divergence, genetic diversity, inbreeding and genetic information retention）, and evaluated their genetic quality. The results show that faint genetic divergence exis- ted between the two stocks （ FST = 0. 016 1 ）, and their genetic diversity level and effective population size of the fingerling stock were lower than those of the natural stock, with higher average inbreeding coefficients and FIS values. It is proved that for genetic diversity, this fingerling stock is inferior to the natural stock, and the genetic quality of the fingerling stock fails to meet the requirement of stock enhancement, so releasing the stock may produce negative genetic effects. Since the deviation rate of effective population size was the highest （ -35.34% ）, the effective population size is considered to be the major genetic quality defect.