Influence of Chronic Man-made Pollution on Bromus inermis Genome Size

Technogenic pollution can accelerate microevolutionary processes in natural populations. We estimated the nuclear DNA content of 10 Bromus inermis Leyss. samples from the Middle and Southern Urals (Russia) by flow cytometry. These populations have grown under different levels of man-made pollution (heavy metals and radionuclides) and background (unexposed) localities. All populations of B. inermis had similar DNA contents, ranging from 21.82 to 23.55 pg/2C. The average DNA content of 22.61 ± 0.45 pg/2C, corresponding to a genome size of 11 056 Mbp/1C, indicates that all tested populations represent the octoploid form (2n = 56). Using a Bayesian linear mixed-effects model, the current materials were compared with previously published data. In general, the DNA contents of the impact populations did not deviate from the background density (p = 0.073–0.983). The current preliminary data do not confirm nor refute the presence of aneuploids in impacted B. inermis populations.