Genomic selection in salmonids: new discoveries and future perspectives

Abstract Over the past 20 years, introduction of new molecular techniques has given a impetus to genetic and genomic studies fishes. The main traits selected in aquaculture sector conform polygenic model, and, thus far, effective breeding programmes based on genome-wide association (GWAS) marker-assisted selection (MAS) have been applied simple (e.g. disease resistance sexual maturation salmonids) known Quantitative Trait Loci (QTLs). Genomic uses relationships between candidate loci SNPs distributed over entire genome tight linkage disequilibrium (LD) with genes that encode traits. SNP (low high density) arrays are used for genotyping thousands markers (single nucleotide polymorphisms, SNPs). expected value (GEBV) candidates is usually calculated by means GBLUP or ssGBLUP step) methods. In recent several programmes, method different fish crustacean species. While routine implementation now largely carried out Atlantic salmon ( Salmo salar ) rainbow trout Oncorhynchus mykiss ), it that, near future, this will progressively spread other However, an expensive method, so be relevant mostly economic value. (using salmonid species), accuracy GEBVs varied from 0.10 0.80 growth rate resistance) compared traditional methods geneology. species potential improve substantially change ongoing systems. long term, ability use low-pass sequencing methods, low-cost novel phenotyping allow animals directly at farm level.