Abstract: The malate dehydrogenase (MDH) isozyme in six subspecies of Apis mellifera, i.e., “Zhejiang Agricultural University” No-1 A. m. ligustica (Ea), A. m. ssp. (Db), A. m. carnica (Cn), A. m. carpatica (Cp), A. m. caucasica (Cc), and A. m. acervorum (Ac), was studied with isoelectrofocusing polyacrylamide gel electrophoresis (IEFPAGE), and their genotype frequency, allele frequency, homozygous and heterozygous degree were analyzed. Ea, Cp and Cc showed high homozygous degree, but the allele with the highest frequency was c in Ea; b in Cp; and a in Cc. Db, Cn and Ac are highly heterozygous subspecies, but the frequency differences of the allele a, b and c in Db were less than the others; and the frequencies of the allele a, c were higher, while the allele b was rare in Cn and Ac. There were highly significant differences in the genotype frequency, the allele frequency and the heterozygous and homozygous degree among six subspecies. These differences provided some genetic clues for the discrimination of six subspecies.

Key words: Apis mellifera, malate dehydrogenase (MDH ), gene, genetic variability