Further characterization of honey bees from the Iberian Peninsula by allozyme, morphometric and mtDNA haplotype analyses

It has been proposed that the Iberian Peninsula served as an important refuge for honey bees during periods of European glaciation. The discovery of genetic markers originating from both African and European honey bee lineages in extant Iberian populations led to hypotheses that the region may be a zone of hybridization or reflect the action of human-assisted translocations. In the present study, we investigated allozyme, mitochondrial and morphological variation in honey bee populations sampled from southern France to northern Morocco. Morphological data supported the interpretation that the bees of Iberia, south and west of a line from Zaragoza to Barcelona, can be characterized as the subspecies Apis mellifera iberica (A. m. iberiensis). There appears to be a narrow demarcation between this subspecies and A. m. mellifera, rather than a gradual cline. The persistence of significant subpopulation differentiation indicates that migratory beekeeping has not strongly influenced the genetic characteristics of local populations. Allozyme data were consistent with previous studies showing north – south changes in allele frequencies, possibly related to subspecific origins or selection. Although mtDNA haplotypes of presumptive A lineage origin were found to be prevalent in Iberian honey bee populations, morphological analysis and published microsatellite evidence does not show a comparatively strong influence from the nearby African subpopulation (Morocco).