Genotype by environment interactions for growth and survival traits of “Pingyou No. 2” flounder (Paralichthys olivaceus) in different aquaculture environment

Aiming to improve the growth and survival performance of “Pingyou No. 2” flounder in different aquaculture areas, in this study, broodstocks which were selected based on the results of genetic parameter estimation and genome selection for growth and resistance traits, wre used to produce “Pingyou No. 2” families. In total, 28 families were produced. Then these families were cultured in different sites (Site 1: Hebei; Site 2: Shandong). Genotype by environment interactions for growth and survival traits were estimated based on mixed linear models. The average daily gain was 1.5 g/d and 1.2 g/d in Site 1 and Site 2 respectively, and the survival rate was 81.4% and 82.2% in Site 1 and Site 2 respectively. Both traits showed a superior performance in two sites. The genetic correlations for harvest body weight and survival traits between both environments were 0.57 and 0.82 respectively, indicating that there was a significant genetic by environment interaction effect for harvest body weight, but not for survival. These results suggest that “Pingyou No. 2” flounder showed good growth and resistance performance in different sites. The harvest body weight and survival traits still have certain selective potential. Hence, to ensure a good demonstration and extension results, it is necessary to improve and optimize the seed production techniques (e.g., seeds with good environmental adaptability) for achieving the advantage of fast growth and high survival rate of olive flounder in different aquaculture environments.