Journal
JOURNAL OF FISH DISEASES
Volume 42, Issue 12, Pages 1657-1666Publisher
WILEY
DOI: 10.1111/jfd.13092
Keywords
disease resistance; genetic correlation; heritability; selection response; selective breeding
Funding
- Ministry of Agriculture and Rural Development, Vietnam [KHCN2013] Funding Source: Medline
Ask authors/readers for more resources
Streptococcus iniae is one of the most serious aquatic pathogens, causing significant economic losses in marine and freshwater species, including Asian seabass (Lates calcarifer). Controlling this gram-positive bacterial pathogen has been an issue in aquaculture systems, due to the combined effects of aquaculture intensification and climatic impacts. To date, there have not been any genetic parameter estimates for S. iniae resistance in Asian seabass. The main aim of this study was to examine genetic variation in S. iniae resistance and its genetic correlations with growth and cannibalism in Asian seabass families produced from a breeding programme for high growth in 2016 and 2017. The study included a total of 5,835 individual fish that were offspring of 41 sires and 60 dams (31 half-sib and 34 full-sib families). The experimental fish were challenged by intraperitoneal injection with a volume containing 10(5) CFU (colony-forming unit)/fish. Resistance to S. iniae was measured as survival rate at 6 hr, 3, 5, 7, 10 and 15 days post-challenge test. There were significant variations in S. iniae resistance among families at different observation periods (ranging from 24.4% to 80%). Restricted maximum-likelihood method and mixed model analysis were applied to estimate heritability for S. iniae resistance. The heritability for S. iniae resistance ranged from 7% to 18% across different statistical models used. The common full-sib effects accounted for 0.1%-2% of the total variation in resistance to S. iniae. Genetic correlations of the S. iniae resistance at 6 hr and 3 days with later post-challenge test periods were low to moderate. However, these estimates for S. iniae resistance between successive measurement times (5, 7, 10 and 15 days) were high and close to 1. The genetic correlations of resistance with body weights at 180, 270 and 360 days post-hatch were not significant as well with cannibalism. It is concluded that there is substantial additive genetic variation in resistance to S. iniae, suggesting there is potential for genetic improvement of Asian seabass for resistance to S. iniae through selective breeding.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available