Biochemical and genetic polymorphism of Bromopsis inermis populations under chronic radiation exposure

For the subsequent assessment of the genetic mechanisms responsible for the resistance of plants to chronic irradiation, the analysis of RAPD-cDNA with the subsequent isolation, cloning, and sequencing of expressed polymorphic sequences is a promising technique. A study was conducted on Bromopsis inermis populations that have been growing for a long time in the EURT area. Using RAPD primers, we studied the genetic spectra of plants. In analysing the UPGMA algorithm, we identified two well-distinguishable clusters with a high level of bootstrap support (> 85%): background samples hit the first, and impact samples hit the second. Our data indicate a decrease in diversity in the most polluted population, as well as the appearance of new alleles in chronically irradiated samples of the B. inermis. Smooth brome seedlings were characterised by the content of anthocyanins, comparable with other types of cereals. In the gradient of chronic irradiation, the relative content of anthocyanins was not significantly changed. For the first time, the partial nucleotide sequences of the key genes of anthocyanin biosynthesis (Chi and F3h) in the brome were determined, these sequences were found to be 191 and 356 bp in length, respectively, and were cloned and sequenced. Three copies of the Chi gene were identified in the B. inermis genome. One copy (BiChi-1) clustered with the sequences of the Aegilops tauschii gene (D genome), and the other two copies (BiChi-2 and BiChi-3) formed a separate cluster in the Pooideae subfamily adjacent to Hordeum vulgare. In the copy of BiChi-1, a complete deletion of intron 1 was detected. For the F3h gene, one copy of the B. inermis gene was obtained, which forms a separate branch in the subfamily Pooideae.