One of the most acute problems for beekeepers around the world is nosematosis, a parasitic disease that can lead to the mass death of honeybees. TSU biologists searched for genetic markers that determine the susceptibility or resistance of bees to various diseases, with the main emphasis on nosematosis. According to the study, the scientists were able to identify potential DNA loci of the dangerous infection.
- An analysis of the state of apiaries in the Tomsk Region showed that a variety of diseases are circulating in the region, among which are two types of nosematosis, A and C,- says Nadezhda Ostroverhova, Associate Professor at the Department of Invertebrate Animals, TSU Biological Institute. - In the first, the bees die because of intestinal damage, but the second form of the disease that is more dangerous is type C. It is an aggressive form that theoretically should not be present in the Tomsk Region due to the cold, but it exists. Nosematosis C is difficult to detect in an apiary, apparently it may not appear at all, and the bees for no apparent reason leave the hive in droves.
It is believed that this disease was the cause of the collapse of bees in Greece, Turkey, and Spain, where thousands of insects died. In the Tomsk Region, a dangerous pathogen was first identified in 2013. Over the past six years, there have been two cases in the region, both in the north - in Molchanovsky and Teguldetsky regions. Massive death of bees was recorded on large semi-industrial apiaries - up to 90% of the total number. The results of the analysis confirmed that the most likely cause of this was the aggressive form of nosematosis.
- We made a selection of conditionally healthy and nosematosis-infected individuals of different breeds (Central Russian, Carpathian, and breeds of karnik bees),- says Nadezhda Ostroverhova. - For research we took only purebred bee families. Using molecular genetic analysis, we looked for distinctive signs indicating the susceptibility of bees to the pathogen. As a result, we discovered a DNA locus (a region on the chromosome) characteristic of all three breeds, potentially significant for determining the risk of the incidence of bees by noseomatosis.
Next, scientists plan to explore in more detail the chromosome regions where this locus is located and will try to identify the genes that play a role in the formation of the bees’ immunity. If this problem is successfully accomplished, biologists will be able to use these markers in bee breeding. First of all, it is important for breeding farms that are engaged in the selection of bees with special characteristics, for example, winter-resistant, with high productivity of royal jelly, and with increased productivity of honey.
A comprehensive analysis of the incidence of bees, conducted by researchers, showed that a variety of pathogens circulate in the Tomsk Region. In particular, fungal infections are common; almost 90% of apiaries are infected with them. The most difficult situation is noted in the Tomsk region. This is due to the high number of amateur farms, which are located at a short distance. Bees from neighboring apiaries, in contact with each other, transmit diseases.
- A big problem is the hybridization of bees,- Nadezhda Ostroverhova notes. -Enthusiasts import peace-loving breeds with which it is easier to work, but when crossbreeding bees, many important characteristics deteriorate, including the insects’ immunity, and their susceptibility to diseases increases. The best option for Siberia is the Central Russian breed, which is well adapted to our climatic conditions and gives very high-quality honey. Its diastatic number (the main indicator of naturalness and maturity of honey) reaches 40-42. Honey with a ratio higher than 30 is considered elite. In Europe, the Central Russian bee is on the verge of extinction. In Russia, this breed must be maintained.