Selection response and realized heritability for growth in three stocks of the Pacific oyster Crassostrea gigas

Abstract

To estimate response to selection and realized heritability for shell height, a one-generation selection was performed in the Pacific oyster Crassostrea gigas using three stocks from China (stock C), Japan (stock J), and Korea (stock K). Applying about the same intensity of selection in the upward direction, three selected and three control lines were created, which were reared under the same environmental conditions at larvae, spat, and grow-out stages. Stock C and stock J showed significantly higher response to selection and realized heritability than stock K at spat and grow-out stages (P \ 0.05). At harvest on day 360, the selected lines of stocks C, J, and K were 12.2, 12.2, and 7.9% larger than their control lines, respectively, for shell height. When averaged across the grow-out period, the genetic gain for stocks C, J, and K was 13.2 ± 1.2, 13.2 ± 1.0, and 7.2 ± 0.7%, respectively, and realized heritability was 0.334 ± 0.028, 0.402 ± 0.024 and 0.149 ± 0.027, respectively. The relatively high realized heritability estimate obtained for stock C and stock J indicates that there is genetic variation in the two stocks and that selective breeding by mass selection is very promising.

Heritability estimates for growth-related traits in the Pacific oyster (Crassostrea gigas) using a molecular pedigree

“…Recently, Li et al . () reported realized heritability estimates for shell height resulting from mass selection ranged from 0.149 to 0.402 in C. gigas at 12 months of age. In other oyster species, heritability for shell height was 0.34 in the Chilean oyster Ostrea chilensis (Toro & Newkirk ); and was 0.11 at 6 months and 0.19 at 18 months in the European oyster Ostrea edulis (Toro & Newkirk ).…”

“…In our study, heritability was the highest for shell height (0.49 AE 0.25). Recently, Li et al (2011) reported realized heritability estimates for shell height resulting from mass selection ranged from 0.149 to 0.402 in C. gigas at 12 months of age. In other oyster species, (Toro & Newkirk 1991); and was 0.11 at 6 months and 0.19 at 18 months in the European oyster Ostrea edulis (Toro & Newkirk 1990).…”

“…Dégremont, Ernande, Bédier and Boudry () reported the heritability estimates for growth varied from 0.07 ± 0.07 to 0.15 ± 0.08 in 6‐ to 8‐month‐old C. gigas . Li, Wang, Liu and Kong () reported realized heritability of shell height to be 0.149 to 0.402, which resulted from one‐generation mass selection in three stocks of the Pacific oyster.…”

Heritability estimates for nutritional quality‐related traits of the Pacific oyster, Crassostrea gigas

“…Evans et al estimated the heritability of shell pigmentation using 18 full‐sib families by midparent–offspring regression, and the result proved to be reliable when compared with other results (Evans, Camara, & Langdon, ). Regarding variation in nutritional quality traits, glycogen, protein, lipid, and Zn contents display high variation among families, which is a basis for selective breeding (Li et al, ). In contrast, Se content did not differ between half‐sib families in this study, and conducting selective breeding for Se content is therefore likely impossible for the population analyzed here.…”

“…Genetic and phenotypical correlations between two traits include specific quantitative trait parameters that can be applied to predict the potentiality of traits to be improved together by selective breeding and be beneficial for determining proper breeding strategies (Falconer & Mackay, 1996). The most recent heritability studies on bivalves focused on traits related to growth (Frank-Lawale & Allen, 2008;Guinez, Toro, Krapivka, Alcapan, & Oyarzun, 2017;He, Guan, Yuan, & Zhang, 2008;Kong, Li, Yu, & Kong, 2015;Li, Wang, Liu, & Kong, 2011;Wang, Du, Lu, & Liu, 2010) and resistance to bacteria and viruses (i.e., to mortality) (Azema et al, 2017;Degremont, Lamy, Pepin, Travers, & Renault, 2015). The heritabilities of lipid percentage in Atlantic salmon and Coho salmon have also been estimated (Sodeland et al, 2013).…”