标记指导大规模混合家系选育技术应用实例

Application of Large-scale Mixed Family Selection Assisted by Microsatellite Markers in Mirror Carp Cyprinus carpio L.

本研究介绍了标记指导镜鲤Cyprinus carpio L.大规模混合家系选育技术的操作步骤及其效果。利用20个微卫星标记分析镜鲤亲本群体雌、雄个体间的遗传距离在0.0120~2.0794之间,其中43.28%的个体间遗传距离位于种内家系遗传配组的最佳"阈值"范围内;用配组软件初次建立了约500个混合家系。将其中约30万尾苗种在相近环境中混合养殖,在1龄(30 000尾/300 000尾)和2龄(300尾/30 000尾)分2次以体质量和体长作为目标性状留种,最终选出300尾优良个体作后备亲鱼,平均体质量(1 564.93±335.05)g,平均体长(35.85±3.10)cm,累计留种比例为1 000∶1。再次用基于亲本遗传背景的配组软件将后备亲鱼划分为20个繁殖系谱,其中15个群组的平均体质量超过预定指标(1 500 g)。本实验结果表明,此技术路线操作简便,选择强度大,所获选育群体系谱清晰,适于苗种生产单位的遗传育种实践。

The procedure and results of marker-assisted large-scale mixed families’ selection is described in mirror carp(Cyprins carpio L.). It was found that the genetic distance was varied from 0.0120 to 2.0794 based on twenty microsatellite markers among the 334 F1 individuals, 43.28% of which met the criterion of intraspecific breeding. About 500 mixed families were established via a breeding software. Three hundred 2 years old mirror carp were selected as candidate brood stock after two rounds of screening with the average body weight of(1 564.93 ±335.05) g, which were selected from 300 000 larval fishes at high ratio of 1 000 ∶1. Furthermore,300-candidate brood stock were divided into 20 groups for selection using the breeding software based on genetic background. The average body weight of 15 groups among the F2 offspring was up to expectation. The findings revealed that the technical route had the convenient operation and clear pedigree, and could be applied in breeding of commercial fishes.