A genome-wide association study of growth traits in “Green Pacific hybrid abalone” (Haliotis discus hannai ♀ × H. fulgens ♂)

"Green Pacific hybrid abalone" is the F1 generation obtained by artificial hybridization of the Pacific abalone Haliotis discus hannai ♀ and green abalone H. fulgens, which has been popular in China's abalone aquaculture industry in recent years due to its advantages of rapid growth. Improving the growth traits of this species contributes to the development of abalone breeding. Therefore, in this study, the genome-wide association study (GWAS) of seven growth traits was conducted in 200 "Green Pacific hybrid abalone" with 521,802 SNPs by super GBS sequencing technology. A total of 88 potentially associated SNPs and 28 potentially candidate genes were identified through annotation. Five genes, cdk2, kif13b, pde2a, prss23, and tmem131l, were selected for RT-qPCR verification, and it was inferred that these genes may indirectly regulate the growth of organisms by participating in cell differentiation, growth regulation, material transport and signal transduction in hybrid abalone at different stages of growth and development. The study also examined the relationships between various genotypes of 27 significantly associated SNPs and growth traits. Nine of them had a heterozygous genotype as the dominant genotype, and they all performed significantly better than the homozygous genotype in terms of growth traits. In conclusion, our findings provide an experimental basis for improving the performance of hybrid abalone and accelerating the breeding process, and these markers and genes can also serve as a starting point for exploring the genetic mechanisms underlying growth in hybrid abalone.