Biodiversity of the honeybee apis mellifera, linne (1758), from some Yugoslav regions. I - The biometric variability of the chromosomes of the Banat and Syenichko - Peshterski ecotypes

Abstract

In this paper are presented the results of comparative biometric studies of the chromosomes of two honeybee ecotypes (the Banat ecotype - BET, and the Syenichko - Peshterski ecotype - SET) from some ecogeographically defined Yugoslav regions. They differ significantly in many microgeographic and microclimatic elements, which may be a cause of the genetic (chromosomal) diversity of the studied species. The biometric analyses indicated differences in the relative chromosome length and centromere index (arm ratio). The greatest differences in the relative lengths of chromosomes were observed between chromosomes 12, 2, 3, 1 and 6 in favour of the SET ecotype, and in chromosomes 15, 14 and 11 in favour of the BET reference ecotype. However, the monitoring of the centromere index revealed the greatest differences between chromosomes 16, 1, 2 and 4. On the basis of these results we advanced the hypothesis that the observed chromosomal biometric differences are the result of the amplification and rearrangement of chromosome regions of the representatives of the studied honeybee ecotypes, but this requires additional confirmation by ultrastructural analyses of chromosomes.