QTL-mapping of individual resistance against American foulbrood in haploid honeybee drone larvae (Apis mellifera)

Abstract

American foulbrood (AFB) is a severe brood disease in honeybees. Since sustainable treatment is not available, selection of genetically resistant honeybee stock is highly desirable. Using a set of 291 heterozygous microsatellite markers in a bulk segregant analysis with subsequent finemapping of haploid drone offspring from a single honeybee queen, we identified one significant and three suggestive quantitative trait loci as well as one significant epistatic interaction influencing prepupal survival after AFB infection. While we were not able to verify specific genes responsible for tolerance, we suggest that developmental genes may have played an important role. The identified markers can be used as regions of interest in future mapping or expression studies. In order to use them for markerassisted selection in breeding programmes for AFB-resistant honeybee stock, it will be required to evaluate these loci more extensively under variable experimental conditions.