2007 Saskatraz Report
Using natural selection and molecular assisted breeding methods to develop productive, gentle honeybees with tolerance to mites and brood diseases.
Albert J. Robertson, Meadow Ridge Enterprises Ltd. Group Site 602, Box 1. RR#6 Saskatoon, Sask. S7K 3J9 Phone 306-373-9140 Email aj.robertson(~)sasktel.net
We are entering into our fourth year of study on the Saskatraz project. This winter and spring a lot of press has been directed at massive honeybee colony losses worldwide. It has brought serious attention to the critical importance of honeybees to life on earth. Managed honey bee pollination is estimated to be responsible for up to one third of the human food supply (Greenleaf and Kremen, 2006, PNAS 103; 13890-13895). Pollination of 90 different plant species including fruits (citrus, stone fruits), vegetables, tree nuts, forage crops, field crops (hybrid canola, sunflowers, cotton, etc.) and other speciality crops have been estimated to be worth 15 billion dollars annually in the USA alone. Reports of catastrophic losses of honeybee colonies worldwide are of grave concern.
A recent report to the US congress by a scientific task force addressing the so called Colony Collapse Disorder (CCD), has not identified a specific cause, but suggests a combination of factors are involved. These factors include parasitic mites (varroa and tracheal), stress levels induced by miticide chemical treatments, transportation, nutrition and, environmental factors (pesticide residues). Chemical residues collecting in the wax (i.e. from miticide treatments), food stores and in the bees themselves could also be a factor. In addition, it has been suggested that the bees in the US lack genetic diversity and that certain lineages may be more susceptible to collapse than others.
Although most honeybee losses in Canada in 2007 have not yet been linked to CCD, most observations suggest high losses (including parts of Saskatchewan) are due to varroa mites becoming resistant to licensed chemical treatments (personal communication-John Gruszka, provincial apiculturist). This suggests it is only a matter of time before the CCD issue emerges in Canada causing serious losses to our commercial beekeepers and other agricultural producers.
The Saskatraz project was initiated in 2004 and supported by the SBA membership, to address most of the issues discussed above. This project is unique in that it has a very large gene pool collected over the past seven years and combines natural selection with powerful molecular assisted selection techniques. We have made some observations at Saskatraz this spring providing strong evidence that varroa and tracheal mites play a crucial role in CCD.
The object of this project is to breed gentle, productive honey bee colonies, with tolerance to mites and brood diseases. Attempts are also being made to correlate tolerant phenotypes with microsatellite DNA markers. Honey bee genotypes showing potential mite tolerance and beneficial economic traits have been and continue to be accessed through out the world, as well as from Canadian populations and established at an isolated yard site designated "Saskatraz". Colonies were initially established in June 2004 at the Saskatraz site, after infection with tracheal and varroa mites, no chemical miticide treatments have been made and natural selection is being allowed to identify tolerant phenotypes.
None of the 35 colonies initially introduced to Saskatraz were found to have tracheal mites (200 bees per colony were tested), but about 30% of the colonies tested positive for low levels of varroa mites in July 2004. Tracheal mites were introduced in the fall of 2004 by adding at least 200 bees to each colony from a colony showing 60% infestation. All colonies tested positive for varroa mites by October 15, 2004.
In April 2005, thirty-two of the thirty-five colonies established in 2004 survived the winter. A detailed phenotypic analysis of the thirty-two queen right colonies was performed and two colonies (SAT-23, SAT-30) were selected. In the spring these colonies showed the best spring populations, brood patterns, pollen stores and low varroa counts. Both colonies tested negative for tracheal mites. Queen cells from these two colonies were produced and distributed to SBA queen breeders for out crossing and evaluation. By July 2005 a total of 48 selected colonies were established at Saskatraz.
In the fall of 2005, six Saskatraz colonies were selected based on honey production, suppression of tracheal and varroa mite population growth and other desirable traits. SAT-14, 17, 23, 28, 30 and 34 were selected for multiplication in 2006. Detailed analyses on these colonies were published in the SBA Newsletter Volume 11, Number 2. Special Edition. 2006. In May 2006, 44 out of the 46 colonies wintered at Saskatraz survived. A11 of the breeders selected in the fall of 2005 showed excellent winter survival and were reselected in May 2006. One thousand queen cells from these selected lines were distributed to about 40 SBA beekeepers. Several breeder queens derived from these selections were "close system" mated at Saskatraz some of which were distributed to SBA queen breeders. A number of these breeders are being evaluated this spring and queen cells will be provided to SBA queen breeders in June 2007 from the best selections.
Extracted from the SBA Newsletter, Volume 12, No. 3, Special Saskatraz Edition.
