EVOLUTION PROCESSES IN POPULATIONS OF PLANTAIN, GROWING AROUND THE RADIATION SOURCES: CHANGES IN PLANT GENOTYPES RESULTING FROM BYSTANDER EFFECTS AND CHROMOSOMAL INSTABILITY

摘要

The viability of seeds growing around the nuclear power plant (NPP) can decrease up to 20-30%. We consider the appearance of both multiple secondary cells and chromosomes with abnormalities. We used the ideas of adaptation to explain these phenomena. The aim was the statistical analysis of the appearances of cells and chromosomes with abnormalities in dependence on radiation factor around the NPP and seeds' antioxidant status (AOS). Methods. The chromosome bridges and acentric fragments were registered as chromosomal abnormalities in root meristems of plantain seeds collected in tested populations. For sites within a 30 km radius of the NPP, the annual γ-radiation dose rates, ~(137)Cs soil concentrations and NPP fallouts were standard and did not exceed norms. Seeds were collected in years with normal and extreme high summertime temperatures. Results. The modelling showed that the appearances of a number n cells (or chromosomes) with abnormalities would be described by the formulas G_n, P_n, G_n + P_n, where P - Poisson and G - geometrical regularities. The parameters of distributions are the AOS- and NPP fallouts dose rate dependent, especially communicative G-component. Due to communication mechanisms, some of cells and seedlings accumulated abnormalities and many others died near the NPP. Conclusions, (ⅰ) statistical biomarker of stress effects is intensification of the communicative processes; (ⅱ) dose-dependent microevolution process is observed (an appearance of new genotypes and their selection) in indigenous populations under the combined effect of NPP atmosphere fallouts and higher summer temperatures; (ⅲ) the communicative processes in meristem are AOS-dependent; (ⅳ) strategies of survival of populations are different for middle-lethal doses and those which do not exceed norms of their ecological niche (stresses).