Genetic differentiation of populations of honey bee ( Apis mellifera L.) and distribution of RNA-containing viruses at the background of epizootia of Varroa destructor on the territory of Udmurtia

Bees Apis mellifera mellifera L. of the Middle Russian breed are resistant to cold winter and a number of diseases, and can effective use short summer for nectar collection. Introgression of Southern bees affects the trait of local Northern breed and changes negatively their adaptation to environment, decreases the immunity and, as a result, increases a susceptibility to ectoparasites and viruses. Mite infestation with Varroa destructor predisposes the bee to viral infection. Assessment of the purity degree of breed affiliation to Middle Russian breed or to dark forest honey bee Apis m. mellifera L. of Udmurt populations of honey bee by the analysis of cubital index (detected by wing parameters) and the study of variation of the intergenic locus COI-COII of mtDNA in PCR was fulfilled. On mtDNA variation, the hybridization in 1UD_S and 5UD_S specimen makes 15.38 и 60.00 %, respectively, and 2UD_S-4UD_S specimen meet the standards of the Middle Russian breed. In 1UD_S-5UD_S, an average cubital index was more than 0.55, so the bees can be referred to Middle Russian breed with high probability. Nevertheless, with regard to variability on the intergenic locus COI-COII of mtDNA, the hybridization with Southern bees occurred in 2UD_S-4UD_S specimen, but not in 1UD_S and 5UD_S. In 2UD_S a heteroplasmy PQ/p3½Q was found. RNA viruses were indicated by RT-PCR in bees under mite infestation with V. destructor. DWV, ABPV and SBV were found in 23.3 %, 13.3 % and 13.3 % of bee colonies, respectively. A combination of two or more types of viruses was identified in 13.3 % of bee colonies, and at least three types were detected in 3.0 %. A simultaneous infection was observed for DWV and SBV, and for DWV и ABPV.