Genetic network analysis between Apis mellifera subspecies based on mtDNA argues the purity of specimens from North Africa, the Levant and Saudi Arabia

OBJECTIVES: This study aimed to analyze the genetic relationships between honey bee subspecies using reference specimens and recently collected specimens from different parts of the world. The purity of these specimens was discussed in light of the obtained results. METHODS: The genetic networks were constructed between 21 subspecies of honey bees, Apis mellifera L.: 9 in Africa, 7 in Europe and 5 in Asia. The analysis was performed using the mtDNA of these subspecies and the Population Analysis with Reticulate Trees software. Some subspecies were represented by more than two specimens based on the available online sequences. RESULTS AND CONCLUSIONS: The subspecies A. m. sahariensis from Africa showed unique characteristics and is genetically isolated than all other studied bee subspecies. Specimens collected from Saudi Arabia showed genetic relatedness to A. m. jemenitica, A. m. lamarckii, and some European subspecies, suggesting high degree of hybridization. The close genetic relationship between the Egyptian bees, A. m. lamarckii, and the Syrian bees, A. m. syriaca, were emphasized. The overall genetic network showed the presence of three distinct branches in relation to geographical locations. The high accurateness of the used analysis was confirmed by previous phylogenetic studies as well as the genetic relationships between hybrid bees of A. m. capensis and A. m. scutellata. The genetic networks showed the presence of bee subspecies from Africa in all branches including Europe and Asia. The study suggests the impurity of some specimens mostly due to the hybridization between subspecies. Specific recommendations for future conservation efforts of bees were presented in light of this study.