Abstract:Edwardsiella tarda is one of the pathogenic bacteria of Paralichthys olivaceus that seriously affects the sustainable development of flounder aquaculture. In the present study, we used the family of high-quality flounder developed in 2012, 2013, and 2014 as the parents, and developed 28 flounder families in 2016, including 4 F3 generation families, 23 F4 generation families, and control family. After 60 days of growth trait assay and artificial bacterial infection experiments, seven families with strong resistance to disease (survival rate > 66%) were screened. F1639 was screened as the F4 generation family with enhanced disease resistance and fast growth rate. Furthermore, its survival rate was 77.23%, which was 32.75% higher than that of the average of 28 families. The daily growth rate was 0.174 cm/d, which was 0.023 cm/d higher than that of the other 28 families. F1639 was derived from the 2007 (F0750, resistant to Vibrio anguillarum family), 2009 (F0927, resistant to V. anguillarum family), and 2014 (F1421, resistant to E. tarda family) families. The results showed that the disease resistance of the breeding families improved. Furthermore, the breeding ability of the offspring can be improved by the breeding of the family (the selection of compatriots). The present study has laid a foundation for breeding new variety of Japanese flounder with higher disease resistance and growth rate. Furthermore, it has important potential application in the genetic breeding for disease-resistant and fast growth stock in other fish species.
