Novel Benedenia disease resistance QTLs in five F1 families of yellowtail (Seriola quinqueradiata).

Benedenia disease is a parasitic disease occurring in cultured marine fish which is caused by the ectoparasite, Benedenia seriolae. This parasitic disease causes serious damage to yellowtail culture due to secondary infections, however prevention methods for the ectoparasite have limited efficacy. Thus, we attempted to initiate a marker-assisted selection (MAS) program to produce a yellowtail strain that has resistance to Benedenia disease. In this study, we conducted a genome scan for quantitative trait loci (QTL) that affect Benedenia disease resistance in five full-sib families using 7910 SNP markers. Sex-specific linkage maps was constructed for the five families and the total number of markers on each map was ranged from 1115 to 1427. We found four significant and five suggestive QTLs affecting Benedenia disease resistance. The phenotypic variation explained (PVE) by each QTL ranged from 8.2% to 29.6%. The QTL with a PVE of 29.6% on LG Squ6 in the family Rr1 was considered to be the major QTL. Novel Benedenia disease resistance QTLs detected in this study enhance our understanding of the genes and genomic regions related to Benedenia disease resistance in yellowtail and can serve as a basis for MAS breeding. • Benedenia disease is one of problems in yellowtail aquaculture production. • A genome scan for QTLs was conducted in five full-sib families. • New QTLs related to Benedenia disease resistance was detected in yellowtail. [ABSTRACT FROM AUTHOR]