Genetic analysis of epistatic effects of growth traits in red common carp

Red common carp are very excellent genetics and breeding materials in aquaculture in China,but the study on their quantitative genetics has not been conducted yet.In this paper,the additivedominanceepistasis genetic model was used to analyzed additive,dominance and epistatic genetic effects for body weight and 10 morphometric traits(total length,standard length,body depth,body width,head length,snout length,eye diameter,iterorbital width,Caudal peduncle length and Caudal peduncle depth) from three variants of red common carp,Cyprinus carpio var.Singuonensis,C.carpio var.Wuyuanensis and C.carpio var.Color,based on F_(2) data from diallel cross experiment.The results indicated: except the trait of body depth,the additive additive epistatic effects were observed in the other traits.In which,the additiveadditive epistatic effects were significant in traits of body weight,total length,standard length,head length,snout length and caudal peduncle length.The proportions of epistasis to phenotype variance of 10 traits were: body weight 11.4%,total length 22.6%,standard length 14.0%,body width 8.3%,head length 24.2%,snout length 17.5%,eye diameter 12.9%,interorbital width 23.1%,caudal peduncle length 5.4% and caudal peduncle depth 20.1%.Through the genetic merit prediction of three parents,it was found that the additive and additiveadditive epistatic effects of C.carpio var.Color could increase the body weight,total length and standard length in progenies,but the these two effects of C.carpio var.Singuonensis and C.carpio var.Wuyuanensis could decease the body weight,total length and standard length in progenies.Epistatic genetic effect could play an important role in genetic selection and breeding in fish.