Evaluation of genetic parameters of growth traits in G2 selected generation of Penaeus monodon

Fifteen whole sib families of the second-generation Penaeus monodon were constructed using artificial mating design in 2020. After labeling the families with fluorescent markers, the growth traits and genetic parameters were evaluated in a cement pond for 56 days. The results showed that the coefficient of variation of growth traits was 11.52-47.53%, indicating a high genetic variation. The heritability range of growth traits of the G2 population of P. monodon was 0.25±0.03-0.41±0.13, which belonged to medium and high heritability, and the statistical test results were significant (P<0.01). The heritability of body length and body weight were 0.38±0.11 and 0.41±0.13, respectively. The evaluation results of genetic correlation among growth traits were highly positive, and the statistical test results were significant (P<0.01). The genetic correlation between body weight and body length was the highest (0.99), and the genetic correlation between the width of the first carapace and the height of the first abdominal segment was the lowest (0.71). The phenotypic correlation between body weight and body length was the highest (0.93), and the lowest was head breastplate width and first abdominal segment height (0.53). These results showed that the G2 generation population of P. monodon has high genetic improvement potential, and the combination of family selection and individual selection achieved better genetic gain. The growth traits were highly positively correlated. Body length and body weight could be selected as the key traits for fast growth line selection, while the other growth traits could be indirectly selected through positive genetic correlation.