Cytogenetic study of natural chironomini (diptera, chiromedae) populations from open water bodies of former Semipalatinsk test site

In the paper genetic variability of natural population of chironomidae inhabiting in waters on the territory of Semipalatinsk test site (STS) is studied. Ten Chironomini species of Chironomidae subfamily and one species of Tanypodinae subfamily were identified using cyto-taxonomic methods of analysis. Cytophotomap of polythene chromosomes of salivary glands were established for four species: Glyptotendipes salinus, Captochironomus setivalva, Camptochriomonus tentas and Chironomus plumosus. For the first time a new previously unknown species of Chironomus gender, and namely C, genelenus 1. sp. n. was described and a cytophotomap of its polythene chromosomes was established. A detailed quantative and qualitative analysis of chromosome polymorphism was carried out and the spectrum and frequency of the disk sequences and genotypic combination were identified. New evidence on change in the polythene chromosomes structure were revealed in certain Chironomini species dwelling in the radioactively contaminated water bodies of STS: rare, unique disk sequences of chromosomes were found, a series of specific homo zygote and heterozygote inversions were observed, which evidently resulted from long-term adaptive selection under conditions of the chronic ionizing radiation. Increase of in frequency of structural mutations of chromosomes was found in mitotic cells of imago disk of Chironomini larvae is revealed. This increase indicates that at the STS many population of benthos organisms are directly affected by the ionizing radiation