Submitted to: Journal of Apicultural Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/24/2012
Publication Date: 2/1/2012
Citation: Holloway, B.A., Sylvester, H.A., Bourgeois, A.L., Rinderer, T.E. 2012. Association of single nucleotide polymorphisms to resistance to chalkbrood in Apis mellifera. Journal of Apicultural Research. 51(2):154-163. Interpretive Summary: Chalkbrood disease results from a fungal infection of the intestinal track of honey bee brood. The fungus especially affects the brood of stressed colonies especially during cold weather, when other pests are present, or during times of low nectar flow. In this study we inoculated larvae with chalkbrood fungus and surveyed for resistance versus susceptibility. We then determined if there is a genetic basis for chalkbrood response by looking for association of genetic markers with the resistant versus susceptible groups of larvae. There is one strong association between a region of the genome and the resistance trait. There are several genes within the region that may be responsible for the resistance. Because we only found one region of interest, a Marker Assisted Breeding Program could easily be developed and used to increase chalkbrood resistance in managed colonies.
Technical Abstract: Chalkbrood is a honey bee brood disease that often affects colonies that are already under stress. Control of the disease can be as simple as ensuring adequate ventilation and food sources or using clean beekeeping equipment. However, when the infection goes unchecked, the overall health and productivity of the colony is greatly decreased. Some stocks of honey bees seem to be more troubled by the disease. Efforts to control rampant infections have not been widely accepted or successful. Identifying a genetic basis for resistance in the affected larvae would be useful for breeding for improved resistance in bee populations. We show a statistically significant association between chalkbrood resistance and a genomic locus. Selective breeding for larval resistance can likely work in concert with breeding for desirable characteristics such that chalkbrood can become a negligible disease among managed colonies.