Maternal Inheritance in Hybrids of Three Honey Bee Subspecies

The identification of honey bee (Apis mellifera) subspecies is often based on the measurements of workers’ fore-wings. The interpretation of the measurements can be difficult because the phenotype of workers is affected by both genetic and environmental factors. Moreover, it is not clear how the phenotype is affected by maternal inheritance. We have used the methodology of geometric morphometrics to verify if hybrids of honey bee subspecies and their backcrosses are more similar to either the father or mother colony. The comparison was based on fore-wing venation of three honey bee subspecies: A. m. carnica, A. m. caucasica, A. m. mellifera. First generation hybrids and backcrosses of those subspecies were obtained through instrumental insemination. Workers of the hybrids were compared with their parental colonies. The shape of wing venation was more similar to the maternal than to parental colony. This phenomenon was particularly visible in first generation of hybrids but it was also present in backcrosses. There were also symptoms of genetic dominance of some subspecies but this effect interacted with maternal inheritance and was difficult to interpret.