Isoenzymic Genetic Variability in Populations of Messor structor (Hymenoptera, Formicidae) from Bulgaria

Genetic variability in 36 populations of Messor structor (Latreille, 1798) from Bulgaria was studied using analysis of two enzymic systems corresponding to four loci (Sod-1, Sod-2, Sod-3 and Me-1). Three of the studied loci were found to be polymorphic. One of them was found to be monomorphic (Sod-3). One to three alleles were detected for the different isozymic systems: one allele at Sod-3 locus (Sod-3100), two alleles at Sod-1 (Sod-1100 and Sod-195) and Sod-2 (Sod-2100 and Sod-297) loci and three alleles at Me-1 locus (Me-1100, Me-198 and Me-196). The observed and expected heterozygosities (Ho and He) ranged from 0.0 to 0.111 and from 0.168 to 0.372, respectively. Allele frequencies of all loci were used to estimate Nei’s (1972) genetic distance, which was found to range from 0.001 (between Boliarino and Lubenova mahala) to 0.462 (between Chirpan and Merichleri). The estimated mean FIS and FST values from isozyme data were 0.8738 and 0.1432, respectively. The Neighbour-joining method and Unweighted Pair Group Method with Arithmetic Mean phylogenetic trees were obtained using genetic distance matrix methods. Two of the studied populations were grouped separately in dendrograms as compared to all other populations which formed a large cluster consisting of three sub-clusters.