中文摘要：

为了培育长牡蛎的高产抗逆新品种,实验采用群体选育方法构建了中国、日本和韩国3个种群的快速生长选育系,2007年至今已连续进行了6代选育。本实验对长 牡蛎选育F3代壳高和活体体质量的增长、选择反应和遗传获得等遗传参数进行了分析。结果表明,从第120日龄开始,中国、日本和韩国3个选育群体的壳高和 活体体质量均显著高于对照组,在420日龄时,平均壳高较对照组分别高13.4%、10.1%和10.5%,平均活体体质量较对照组分别重18.5%、13.4%和11.6%;壳高的平均现实遗传力分别为0.447±0.226、0.471±0.297和0.367±0.167,表明适于对壳高的生长速度进行进一步的选育。长牡蛎中国、日本和韩国选育F3代活体 体质量的遗传获得平均值分别为16.01%±3.82%、15.03%±5.21%和11.57%±5.15%,表明对长牡蛎壳高的生长速度进行选育时,活体体质量的生长速度也得到了明显提高。本研究结果可以为长牡蛎快速生长品系的连续选育提供依据。

英文摘要：

The Pacific oyster Crassostrea gigas,naturally occurring in Japan,China and Korea,is a major global aquaculture species.It is economically important and has had the highest worldwide production in any cultured aquatic animal species since 1993.China produced over 3.5 million tons of cultured oysters,and C.gigas is one of the most important species.In view of the importance of this species,conventional selections have been carried out worldwide in order to increase growth rate,and to improve survival.However,nearly all the broodstock of oyster used remains unselected in China.In order to improve the productivity traits of C.gigas,a selective breeding program for faster growth was initiated in 2006.From 2007,successive generation of mass selection for fast growth in shell height was conducted in three C.gigas stocks from China,Japan and Korea.The progeny of the third generation of the three C.gigas breeding lines（CS3,JS3,and KS3）were compared with the controls in a 420-day farming experiment.Mean shell height and mean total weight of the oysters from all three selection lines were significantly greater than those of controls（P〈0.05）,respectively.At harvest on day 420,the increase in shell height for the three selection lines over the controls were 13.4%,10.1% and 10.5%,the increase in weight were 18.5%,13.4% and 11.6%.In the third generation of three C.gigas breeding lines,the realized heritability of shell height were 0.447±0.226,0.471±0.297 and 0.367±0.167.In addition,the genetic gain of total weight for the CS3,JS3,and KS3 was 16.01%±3.82%,15.03% ±5.21% and 11.57%±5.15%,respectively,demonstrating that total weight had been improved markedly during selection for shell height.These results indicate that the selection for fast growth achieved encouraging progress in the third generation of C.gigas breeding lines.