The bay scallop Argopecten irradians concentricus was introduced to China from South America in 1991. The individuals chosen for this experiment were the F3 offspring of the largest scallop, in terms of shell height, bred from the years 2005 to 2007. Twelve adults were randomly selected from this population with a se-lection pressure of 5%, and 12 self-fertilizing, hermaphrodite families were established. The control group (L0) was produced by mixed crossing of the F3 offspring of this scallop. Kung breeding and comprehensive evaluation values were evaluated in the self-fertilizing family and the control group by inspecting indices such as growth and survival of the offspring. The aim was to breed excellent self-fertilizing scallops and provide the material basis for genetic improvement of the stock. The results showed that there were no significant differences between the fer-tilization rate of the self-fertilizing families and the control group. However, the hatching rates were significantly higher(P<0.05), and families B3 and C2 were the top two, then L0 followed. In the larva stage, the daily shell length growth was significantly higher in B3 and C2 than in the control group, but was significantly lower in the other self-fertilizing families (P<0.05). The survival rates of B3 and C2 were significantly higher than the control group, yet they were significantly lower than the control up to 4 months old (P<0.05). During this period, the self-fertilizing families B3 and C2 displayed significantly higher growth rates than the others in terms of shell height, shell width, and body weight (P<0.05). The comprehensive evaluation and breeding value of the four traits of the different family lines were B3 >C2 >L0 >A3 >B4 >A1 >C4 >B1 >A2 >B2 >C3 >C1, which proved that B3 and C2 were two excellent self-fertilizing families. In the 12 families, self-fertilization depression occurred to some extent in nine, one failed and two (B3, C2) exhibited superior growth and survival. We conclude that it is feasible to es-tablish high quality self-fertilizing families with large-size shell height, improving breeding efficiency, and short-ening the breeding period.% 从1991年引进、并于2005—2007经过3代大壳高群体继代选育的海湾扇贝南部亚种(Argopecten irradians concentricus Say)选育系 F3养殖群体中,以5%的选择压力选取最大壳高个体(高值亲本)作为育种群体,从中随机挑选12个性腺成熟的个体作为亲本,利用其雌雄同体的特性建立12个自交家系,并与 F3群体随机混交后代作对照,考察各家系后代的生长、存活等指标并采用 Kung 育种值及综合评定值对其进行评价,以期选育优秀自交家系,为该品种遗传改良提供物质基础.结果显示,各自交家系与对照组间受精率没有显著差异,但孵化率则存在显著差异(P<0.05),以 B3、C2家系最高,其次为对照组(L0)；在幼虫生长阶段, B3、C2家系幼虫壳长日增长显著(P<0.05)高于对照组,其他家系则显著(P<0.05)低于对照组；在养成期的4月龄,各组别的存活率以 B3、C2家系显著(P<0.05)高于对照组,对照组显著(P<0.05)高于其他家系；4月龄个体的壳高、壳宽和体质量等生长指标,以 B3、C2家系显著(P<0.05)高于对照组,对照组又显著(P<0.05)高于其他家系；各家系各指标的 Kung 育种值(Z)及综合评定值(Pi)的大小排序均呈现 B3>C2>L0>A3>B4>A1>C4>B1>A2>B2>C3>C1.研究表明,12个自交家系中,9个产生了一定程度的自交衰退,1个败育,2个(B3、C2)表现出显著的存活和生长优势,成为超越 L0的两个优秀家系.研究证明,利用高值亲本可提高优秀自交家系命中概率,提高选育效率,缩短选育周期.
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