Population differentiation and racial admixture in the Africanized honeybee (Apis mellifera L.)

Abstract

The authors collected worker bees from 3 regions of Brazil (the NE, the state of Sao Paulo, and Porto Alegre) and from Uruguay and determined their genotypes for 10 enzyme loci. They also performed a morphometric analysis on forewing measurements. There are significant differences, especially at the Mdh locus, among the populations from different regions. Racial admixture was calculated from information obtained for Mdh in Africa and Europe. The percentages of racial admixture differed slightly but significantly among Brazilian regions. The greater proportions of Apis mellifera adansonii alleles in the admixture may be explained by selection during the initial stage of migration of Africanized bees and by preferential mating between individuals of the same race. Differences in the proportions of A. m. adansonii alleles between regions indicate incipient populational differentiation of Africanized bees. Greater gene flow from the European races in the S of Brazil could be one of the causes of this phenomenon. -from Authors