Genetic Profile of Greek Indigenous Honey Bee Populations, Local Extinctions, Geographical Distinction, and Patterns, by Using mtDNA COI and Nuclear CSD Gene Analysis Markers

Evaluation and conservation of local genetic resources of the domestic honey bee populations is important, especially in regions with high diversity levels as well as high honey bee colony density. Greece is rich in honey bee biodiversity, hosting several subspecies, with the status of them being, though, doubtful. The purpose of the present study was to investigate the genetic relationships of both stationary and movable honey bee populations, originating from many location throughout Greece. Two molecular markers were utilized, namely, the conserved mitochondrial COI gene and the highly variable complementary sex determination (CSD) gene. Samples were collected from nine distant populations: eight populations from colonies that followed the traditional stationary beekeeping model and one following the modern migratory beekeeping model type, where the hives are transferred from place to place according to the season. Regardless the beekeeping model, all populations were characterized by sufficient genetic diversity indicating no signs of inbreeding or any bottleneck effects. Nevertheless, genetic differentiation and phylogenetic analysis in comparison with haplotypes obtained from GenBank revealed a genetic admixture pattern suggesting that movement causes genetic homogeneity, occasionally in the stable reared populations as well. Interestingly, two populations, namely, Kastoria and Protokklisi, belonging to A. m. macedonica population, were significantly differentiated, supporting the maintenance of their genetic integrity. Unfortunately, on the other hand, genetic structure of the populations from Crete (Sasalos population) provided evidence that the indigenous breed from the island, A. m. adami, has probably gone extinct. Future management strategies should focus on the conservation of the local genetic resources in which distinct genetic identity has been sustained.