[Alteration of polymorphic systems of Centaurea scabiosa L. under chronic irradiation]

Isoenzyme and morphological polymorphism alteration in populations of perennial grass Centaurea scabiosa L. (scaly cornflower) has been studied. These populations exist on the territory of East Ural Radioactive Trace more than 40 years and are chronically exposed to beta-irradiation. Directional shift of allele frequencies on the loci Per1, Pgi2, Sod1, Lap has been detected. The fact of accumulating genetic load by chronically irradiated populations has been demonstrated. Possible reasons of discovered alterations are discussed. The analysis of the obtained data shows that the irradiated populations have greater similarity with one another than with a control, but relation between genetic distances and accumulated doses hasn't been revealed. The hypothesis is that an extra factor--gene flow from a "clean" territory influences the genetic structure of irradiated populations.