Progress in marker-assisted selection for honey bee breeding

Most economically-desirable traits in honey bees show considerable levels of heritability and thus can be improved via artificial selection. The honey bee’s high recombination rate requires that new approaches for identifying stable markers for selective breeding be considered. To that end, our team previously developed a novel approach to marker identification, notably the discovery of protein expression patterns that were highly correlated with specific behavioural traits, which were then used to enrich hygienic behaviour across several hundred colonies in Western Canada. This produced stock with improved disease resistance, Varroa tolerance, economic performance and winter survival.

Based on our previous success, we have now embarked on a large-scale study to combine proteomics and genome-wide association for identifying highly discriminant markers for bee breeding. The aim of our project is to measure 12 economically-valuable traits of honey bees (colony phenotypes) and develop genomic and proteomic markers that will enable beekeepers to rapidly select and breed healthy and productive colonies, well adapted to the Canadian climate.

In the first year of our study, 1025 colonies from across Canada were phenotyped for the following colony-level traits: Varroa mite population growth, grooming, hygienic behaviour, defensiveness, honey production, brood area, pathogen abundance, innate immunity, gut microbiota and overwintering success. As anticipated, significant correlations were found among similar productivity phenotypes such as fall and spring colony weights (r2 = 0.8374; P < 0.001), as well as between instantaneous and total honey production (r2= 0.6905; P < 0.001). We are continuing to model and analyze these data to determine predictive relationships, which will be further discussed. Progress in identifying proteomic and SNP markers for economically-desirable traits will be reviewed along with implications for improved methods for trait selection.