The role of molecular genetic variation and population structure in the genetic improvement of the honeybee, Apis mellifera

Abstract

Animal breeding has evolved into a highly sophisticated field, making substantial changes to numerous livestock species worldwide. Such changes are largely absent in the Western Honeybee, Apis mellifera. Direct transfer of methodologies can be difficult due to differences in animal biology and production systems. Largely as a result of the high importance of honeybee pollination to agricultural production, beekeeping industries worldwide are changing their management strategies and moving towards large-scale migratory beekeeping. With trucks of bee hives being moved across countries, honeybee stocks are not able to adapt to their shifting environment without targeted breeding efforts. While specific issues facing the global honeybee population such as disease or nutritional challenges can currently be managed by the beekeepers, challenges to honeybee health could be more efficiently and permanently addressed with directional selection towards more robust, disease resistant honeybee stocks suited to large-scale beekeeping. Despite a general awareness of the importance of genetics in the global beekeeping community, use of modern animal breeding methods in honeybee breeding has been low. Barriers to the genetic improvement of commercial honeybee populations range from lack of pedigree data to low adoption of improved stocks by the beekeeping industry. By working closely with commercial operators, honeybee breeding programs can be focused on genetic sustainability as well as economic impact. Through industry involvement, adoption of improved genetics can be insured, while the absence of pedigree can be overcome with the use of affordable genotyping. This dissertation outlines some of the fundamental requirements for the establishment of a modern performance-based honeybee breeding scheme. Biological issues surrounding honeybee genetics and mating habits and can be managed with the use of genomic information. A method for the high-throughput genotyping of living honeybee queens using Genotyping-by-Sequencing is presented, and the practical implications of the availability of information on genetic variation and population structure are discussed. Necessary steps towards constructing a preliminary economically focused breeding objective for the modern honeybee are described and potential traits of importance in a honeybee breeding scheme discussed. In closing, some practical considerations for the design and implementation of a commercial honeybee breeding programme are outlined.