壳金长牡蛎家系的建立及生长和存活性状的比较

于2014年6月,以经过2代家系选育和2代群体选育共连续4代选育的壳金长牡蛎为亲本,采用巢式设计,成功构建25个全同胞家系,同时以未经选育的壳色即普通灰白色的个体子代为对照组,评估各家系和对照组在幼虫、稚贝期的生长和存活差异。结果显示,不同时期,壳金长牡蛎选育家系各生长性状平均值均高于对照组平均值,其中在幼虫期不同日龄,壳金长牡蛎所有家系壳高和存活率平均值均高于对照组,分别提高2.27%~16.67%和1.72%~9.40%;在稚贝期各阶段,壳金长牡蛎所有家系壳高、壳长、总重量及存活率的平均值均高于对照组,分别提高10.04%~19.79%、6.56%~17.78%、10.44%~32.92%和0.20%~4.26%;不同壳金家系间的生长及存活性状具有显著差异,排序也存在不一致性,其中G19和G28家系表现出较高的生长及存活性能,在11月龄,G19和G28家系的壳高、壳长、总重的累积生长量比所有家系平均值分别提高4.78%、8.22%、12.38%和7.61%、4.02%、9.04%,与对照组相比,分别提高15.31%、15.31%、24.11%和18.42%、10.85%、20.42%;存活率比所有家系平均值和对照组分别提高11.70%、12.71%和11.92%、12.94%。研究表明,壳金长牡蛎选育群体的生长性状具有一定的优势,但存活性状有待进一步的改良;家系G19和G28可作为优良品种培育的育种材料。本研究为培育快速生长和存活率高的壳金长牡蛎新品种提供了基础资料。

Construction and comparison of growth and survival among different golden shell families of Pacific oyster (Crassostrea gigas)

In order to select the most outstanding groups of Pacific oyster (Crassostrea gigas) with golden shell color, a total of 25 full-sib families were constructed successfully by using the method of nested design in June 2014. These parental breeders were individuals of C. gigas with golden shell cultured in 2013, which had been selected for four generations by families breeding and populations breeding based on golden shell coloration. In the meanwhile, we produced the control families by using unselected individuals as parents. We measured and compared the phenotypic growth traits and the average survival rates among these families during the larval and juvenile stages. The results indicated that the average values of the growth performances and the survival rates of these golden shell families were greater than those of the control, at the larval stages, the shell height and the average survival rates of all the golden shell C. gigas families were greater than the average values of the control by 2.27%~16.67% and 1.72%~9.40%, respectively; at the juvenile stages, the shell height, shell length and total weight and the average survival rates of all the golden shell C. gigas families were greater than the average values of the control by 10.04%~19.79%, 6.56%~17.78%, 10.44%~32.92% and 0.20%~4.26%, respectively. The differences in growth and survival rates were significant among these full-sib families, based on the great performance of fast growth and high survival, the G19 and G28 were the most excellent families of all the golden shell families of C. gigas in early and medium terms. At the age of 11 months, the shell height, shell length and total weight of G19 and G28 were greater than the average values of the total families by 4.78%, 8.22%, 12.38% and 7.61%, 4.02%, 9.04%, respectively, and were greater than the average values of the control by 15.31%, 15.31%, 24.11% and 18.42%, 10.85%, 20.42%, respectively. The average survival rates of these two families were greater than the average values of the total golden shell families and the control by 11.70%, 12.71% and 11.92%, 12.94%, respectively. Our results suggest that the growth performance superiority of the C. gigas with golden shell coloration is significant and the potential for the selection of the survival rate needs to be studied. The families G19 and G28 can be used as valuable genetic materials for the following breeding and relative research. Furthermore, these results may also provide theoretical supports for genetics and breeding programs of golden shell Pacific oysters.