Developmental quantitative genetic analysis of body weight and morphological traits in red common carp, Cyprinus carpio L.

Developmental genetic analysis was conducted for body weight, total length, standard length and body height in red common carp by a mixed genetic model with additive–dominance effects, based on complete diallel crosses made by Xingguo red common carp (Cyprinus carpio var. singuonensis), purse red common carp (Cyprinus carpio var. wuyuanensis) and Oujiang color common carp (Cyprinus carpio var. color). Unconditional genetic analysis revealed that the traits of body weight, total length and standard length were mainly controlled by dominance effects before June but by additive effects after June, which suggests a high potential for heterosis during the early developmental period and an opportunity for selection during the late developmental periods for common carp. Through conditional genetic analysis, lots of new expression of genes of additive effects for body weight, total length and standard length existed during April to August and significant new expression of genes from dominance effects for these three traits at the other period. New expression from additive and dominance effect genes for body height occurred intermittently during the ontogeny. The conditional genetic procedure is a useful tool to understand the expression of genes controlling developmental quantitative traits at a specific developmental period (t − 1 → t) during ontogeny. It is also important to determine the appropriate developmental period (t − 1 → t) for trait measurement in developmental quantitative genetic analysis in fish.