Evaluation on the genomic selection in Litopenaeus vannamei for the resistance against Vibrio parahaemolyticus

Vibrio parahaemolyticus (V. parahaemolyticus) carrying the toxic plasmid of pirA and pirB has been identified as the causative agent of acute hepatopancreatic necrosis disease (AHPND), which has caused serious economic loss to the aquaculture industry of penaeid shrimp Litopenaeus vannamei (L. vannamei) in recent years. To effectively control the outbreak of this disease, breeding of Vibrio resistant broodstocks of L. vannamei was regarded as an important approach. Due to the advantages in selection accuracy and efficiency, genomic selection (GS) was expected to be a feasible alternative to accelerate the genetic improvement of disease resistance traits. In the present study, the heritability of shrimp resistance to V. parahaemolyticus was estimated and the feasibility of GS was evaluated in L. vannamei based on the real and simulation data. The heritability of shrimp resistance against V. parahaemolyticus was around 0.15-0.24, which indicated that the genetic improvement can be achieved by selective breeding. Subsequent analysis for GS based on real data showed that the genomic best linear unbiased prediction (GBLUP) can result in more accurate prediction than the traditional pedigree-based best linear unbiased prediction (PBLUP), with a 6.8% increase in the prediction accuracy for the survival time, and a 3.5% increase for binary survival. Similarly, for the simulated data, a relative increase (3.0% and 5.0%) in the prediction accuracy was obtained for survival time and binary survival when comparing the PBLUP to GBLUP. Overall results suggest that GS could be an alternative approach to improve the genetic gains in L. vannamei for the resistance to V. parahaemolyticus.