Study Malate Dehydrogenase II Alleles And Combining Ability And Heterosis Of Western Honeybee (Apis MelliferaL.)

There are over 7 millions honeybee colonies in China, among them about 5millions are western honeybee (Apis mellifera L.), and 2 millions are easternhoneybee (Apis cerana F.). In western honeybee subspecies, ligustica (A.m. ligustica)is absolutely dominant; besides this, there are also carnica (A.m.caarnica), northeastblack honeybee (A.m.spp.), caucasica (A.m.caucasica), carpatica (A.m.carpatica)and acervorum (A.m. acervorum) and so on. Malate dehydrogenase (MDH) ofwestern honeybee shows three active enzyme zones, MDHâ… , MDHâ…¡ and MDHâ…¢respectively. MDHâ…¡shows polymorphism, and is controlled by a, b, c three alleles,the zymograms coded by these alleles are located at pH 6.7, pH 7.2 and pH 7.5,respectively In diploid female honeybee (queen or worker) developed from zygotes,six genotypes aa, ab, ac, bb, bc have been found, cc. On electrophoresis patternhomozygote shows one band and heterozygote three, it is a dimer enzyme.Combining ability is the relatively combining capacity between different strains.There are very few available of literatures on the combining ability in honeybee. Incross breeding, parent phenotypes are sometimes quite different from their progeny'sdue to the differences of combining ability therefore selecting parents with highcombining ability is of greatly important. In view of these problems, the geneticvarability of MDHâ…¡in ZAC-1 ligustica, northeast black bee, carnica, caucasicaand acervorum, and in reciprocal cross progeny between ZAC-1 ligustica and theother subspecies were studied; the correlation between MDHâ…¡allele frequency andeconomic traits were also discussed. Furthermore, the combining ability andheterosis of six subspecies in honey, royal jelly, bee pollen, and bee wax and beevenom were analyzed, and the main results obtained were presented as follows:l. ZAC-l ligustica had three genotypes (ac, bc, cc), of them cc was the mostcommon type, and c alleIe frequency preponderant. Northeast black bee had fourgenotyPes (ab, ac, bc, cc), and their frequencies were similar; c allele frequency wasthe highest, but a and b allele frequencies were also very high. Caoptica bad fourgenotypes (ac, ac, bb, bc), bb was the most common tyPe; b allele occurred with thehighest frequency Caucasica had fOur genotypes (aa, ab, ac, bc), aa was the mostfrequent type; a allele was the dominant. There were fOur genotyPes (aa, ab, ac, cc)in camica and five (ap ab, ac, bc, cc) in acervorum, ac was the moSt frequent type;and they showed a, c alleles were high frequently and b was the minimal one. ZAC- lhguStica carPatica and caucasica showed highly homozygous degrees, butnortheast black bee, carnica and acervorum were highly heteroZygous subspecies.2. The distribution of MDH lI allele frequencies in westem hOneybee subspecieswas different, a aIlele shOwed a high frequency in African honeybee (A.m.scutella)or Africanized honeybee; b was dominant in mellghrra (A.m.melldera); and cprevalent in ligustica. Because of commercial export, the proportion of the alIele a, b,c in populations was different, which renected the variability of bIood compositionand genetic origins to some extent. Therefore ZAC-l ligustica was of lghtica blood;carPatica was ofmeUghra origin; and caucasica was closer to African bee; northeastblack bee was the hybrid of three tyPes, but with most hgutica blood; carnica andacervorum were the hybrid of African bee and Ityustica, and had a small percentageof meUdera bIood. Carnica and acervorum's allele frequencies showed nodifferences, and their genetic relationship was close to each other; but both genotypefrequency and heterozygous degree exhibited highly significant deviations, so theywere two completely different subsPecies.3. When ZAC-l ha,tica was reciprocal cross with the other subspecies, thedifferences of MDH II genotype frequencies, allele frequencies and homozygous andheterozygous degrees betwCen progeny and the female parent were smaIler than...