Mitochondrial DNA Variation in Honey Bee (Apis mellifera) Colonies from Urban Districts of Beijing

After the introduction of various Apis mellifera subspecies into China, prolonged breeding and selection have substantially altered the genetic structure and diversity of commercial populations. Currently, A. mellifera has become the most widely managed and numerically dominant honey bee species in China, providing important agricultural pollination services and substantial economic benefits. Nevertheless, the genetic diversity and progenitor of commercially managed A. mellifera populations within different regions in China remain poorly understood. To assess the maternal lineage diversity of A. mellifera populations and to support regional breeding strategies, we examined DNA sequence diversity in the cytochrome C oxidase I (COI) and tRNAleu-COII gene segment of the mitochondrial genome in 178 samples of A. mellifera drones from 12 sites in the urban districts of Beijing. Three haplotypes were found for the COI gene segment, and eight haplotypes were discovered for the tRNAleu-COII gene segment. Mitochondrial sequencing revealed that the frequency of C evolutionary lineage dominates in A. mellifera populations in Beijing. In addition, one unexpected haplotype from the Z lineage was detected. The subspecies Apis mellifera ligustica, representing the C1 haplotype, demonstrates the widest distribution and highest frequency. Our results also showed that significant genetic differentiation exists among commercial populations of A. mellifera in the urban districts of Beijing.