The family line establishment of the hybrid Epinephelus moara (♀) ×E. lanceolatus (♂) by using cryopreserved sperm and the related genetic effect analysis

Hybridization is a way to establish a new gene combination and important genetic progress, through which various desirable traits can be combined to improve varieties. In this study, eggs from 27 females of Epinephelus moara were fertilized with cryopreserved sperm from 4 males of E. lanceolatus, and 28 paternal half-sib families were constructed. At 130d post-hatch, 5 traits including full length, body length, head length, body height and body weight, were measured in 1294 fries from all the families and analyzed by using One-Way ANOVA. Maternal or paternal genetic effects were predicted by using mixed linear model. Variances of five traits were analyzed by using minimum norm quadratic unbiased estimator (MNQUE). Genetic correlation and heritability were analyzed by using " Additive-dominant” genetic model. Maternal and parental additive and dominant random genetic effects were predicted by using adjusted unbiased prediction (AUP). The results showed that significant or extremely significant differences existed in the additive, dominant, genetic and apparent genetic correlations among five traits. Narrow heritability of five traits ranged from 0.521±0.020 to 0.805±0.018, while broad-sense heritability ranged from 0.521±0.017 to 0.832±0.011. Five traits of seven female parents (5766, 6436, 5779, 5798, 5782, 6440, 5790) among 27 gained extremely significant positive additive effect, and one male parent (♂ 8920)among four gained extremely significant positive additive effect. Growth indexes in their offspring were significantly higher than those in other families. Growth indexes of head length, body height and body weight among seven hybrid combinations (5766*5777, 6436*8932, 5779*8932, 5798*8932, 5782*8932, 6440*8920, 5790*8920) among 28 gained significant or extremely significant positive dominant effect. This was the first study to take distant hybridization between E. moara and E. lanceolatus by using cryopreserved sperm and to predict their genetic effects, which provided solid scientific basis for the development of distant hybridization techniques and new variety breeding in groupers.