Comprehensive performance evaluation of Vibrio resistance strains from selective breeding in the Pacific oyster, Crassostrea gigas

Understanding the production performance of newly developed strains in the field is essential for the successful implementation of breeding project and promotes the sustainable development of aquaculture. In this study, a comparative analysis of growth and survival traits between the selectively bred Vibrio-resistant strain and the control population across multiple growth stages and geographic locations was conducted to evaluate the impact of selective breeding and environmental variation on these economically critical traits in Crassostrea gigas. The results showed no significant differences in performance during the larval stages between the Vibrio-resistant strain and the control population. In field, the Vibrio-resistant oysters showed significantly higher shell heights compared to the control population, notably in the Rushan sea area. The Vibrio-resistant oysters consistently demonstrated superior survival rates, particularly in the Rongcheng area. Genotype and environmental factors significantly influenced growth and survival, with a higher impact of environmental factors. The interaction between environment and genotype was relatively weak, but there was a significant impact on survival at 300 days and growth at 400 days (P < 0.05). The aggregate breeding value obtained by economically weighting the breeding values of growth and survival traits revealed that the Vibrio-resistant strain possessed higher economic value and application potential. This study provides valuable empirical data on resistance breeding in oysters, which enhances our understanding of the progress of oyster resistance breeding, and facilitates the cultivation of more robust and resistant oyster varieties.