Abstract
Two hybridizing European species of fire-bellied toads,Bombina bombina andB. variegata, have alternate electromorphs fixed at a number of allozyme loci. Segregation of alleles at seven allozyme loci (Ldh-1, Mdh-1, Ak, Ck, Gpi, Np, andEst-β) was studied in a backross progeny of an F1 interspecific hybrid male and aB. bombina female. Mendelian inheritance of allozyme forms at all seven loci was ascertained. Except for two loci,Gpi andEst-β, which were found to be tightly linked (1 cM apart), other loci showed independent segregation.