长牡蛎壳金选育群体生长性状的选择效应

长牡蛎是一种世界性的养殖贝类,同时是我国最重要的经济贝类之一,壳色美观和快速生长是目前长牡蛎遗传育种的2个重要目标。2010年通过长牡蛎壳色性状的家系选育,获得了壳白、壳黑、壳金和壳紫4种壳色品系。实验以第二代壳金品系为基础群体,对长牡蛎壳金群体的生长性状进行定向选育,分析了长牡蛎壳金选育群体壳高性状的选择反应、遗传获得和现实遗传力。结果显示,养成阶段选择组的壳高均大于对照组,350日龄后表现出显著的生长优势;幼虫期,壳高性状的平均选择反应、遗传获得和现实遗传力分别为0.549±0.277、3.717%±2.611%和0.339±0.171,养成期分别为0.436±0.138、8.253%±1.014%和0.270±0.086。选择组的贝壳金黄色和外套膜金黄色比例分别提高了22%和10%。研究结果为长牡蛎壳金优良品系培育提供了重要基础资料。

Selection response in mass selection of golden shell Pacific oyster (Crassostrea gigas)

The Pacific oyster (Crassostrea gigas) is a major global aquaculture species and a commercially important shellfish species in China. Beautiful shell color and fast growth are two important goals in Pacific oyster genetic breeding at present. We initiated selective breeding of shell color traits via family selection in 2010, and obtained four kinds of shell color strains including white shell, black shell, golden shell and purple shell. In the present study, the selection response, genetic gain and realized heritability of mass selection for shell height based on second-generation golden-shell families were analyzed. The results showed that shell height of the selected strain was greater than that of the control strain during the grow-out stage and the selected strain presented significant growth superiority after 350 d. The average selection response, genetic gain and realized heritability were 0.549±0.277, 3.717%±2.611%, 0.339±0.171 respectively, during larval stage, and were 0.436±0.138, 8.253%±1.014%, 0.270±0.086 during grow-out stage. In addition, golden shell and golden mantle proportion in the selected strain were increased by 22% and 10% compared with that of control strain, respectively. The information obtained in this study is of great significance for the selective breeding of golden shell Pacific oyster.