S. Mahunka szerk.: Folia Entomologica Hungarica 48. (Budapest, 1987)
quencies. Indices of polymorphism and genetic diversities are also shown in Table 2. fn the calculation of the genetic diversity the following formula was used (IZSÁK 1982): H = -EPj • log Pi where H diversity, Pj genotype frequencies. Comparing the three large regions it can be concluded that populations from the Central Tisza Region (1) seemed to be most polymorphic ones. Indices of polymorphism were slightly smaller in populations from the Hernád and Sa|6 Valley (3) while populations from Bereg (NE) Plain (2) seemed to be hardly polymorphic at all. There was no significant difference between the populations collected early in September and late in October. These results are In good agreement with other investigations in the surrounding countries. Adh in Drosophila hydei and Drosophila immigrans Populations of both species were monomorphic at this locus. This is in good agreement with those findings by BATTERHAM et ai. (1983). Odh in Drosophila melanogaster Figure 6 shows the observed genotype frequencies and Table 1 contains gene frequencies. The indices of polymorphism and genetic diversities are presented in Table 4. Populations have been found to be less polymorphic for the zygotes and rare alleles seemed to be on the border of polymorphism. The genetic diversities were considerably smaller than at the Adh locus. Thus, there were not much differences between the regions, but this comparison showed similar tendencies to those of the Adh locus. In distilleries flies are grown on mash with rather high alcohol concentration. On the basis of our results it seems that the ODH enzyme is somewhat more sensitive to the alcohol concentration than the ADH. Odh in Drosophila hydei The genotype frequencies are presented in Fig. 7 and values of gene frequency are shown in Table 1 . Indices of polymorphism and genetic diversities are in Table 4. Three alleles have been found at this locus, however, the populations were not polymorphic. The rare alleles appeared mainly in the populations from the Central Tisza Region (1). It also supports that in this region polymorphism is favoured for all of the Investigated loci. Odh in Drosophila immigrans The species is monomorphic at this locus. Mdhjyj in the three Drosophila species All the investigated species are monomorphic here. Mdhg in Drosophila melanogaster Table 2 shows the allele frequencies, the observed genotype frequencies are depicted in Fig. 8. Values of genetic diversity and indices of polymorphism are presented in Table 5. Populations were polymorphic at this locus. It is interesting, however, that at the Mdhg locus the level of polymorphism is not higher than at the Adh locus. Comparing the three regions it is clear that the least polymorphic populations at this locus, as well as at other loci, are from Bereg (NE) Plain (2). Mdhg in Drosophila hydei The observed genotype frequencies are presented in Fig. 9. Table 2 contains the allele frequencies and Table 5 the ( indices of polymorphism and genetic diversity.
