PH09 Plant Ecotoxicology
Exhibit Hall
8:00 AM - Thursday

(PH113) Variation in non-coding DNA in Chornobyl plant populations.

Tsyusko, O.1, Smith, M.1, Oleksyk, T.2, Glenn, T.1, Smith, M.2, 1 Savannah River Ecology Laboratory, The University of Georgia, Aiken, SC, US2 National Cancer Institute, National Institute of Health, Frederick, MD, US

ABSTRACT- Radiation induced DNA changes are expected for plants and animals living in radioactively contaminated sites, such as Chornobyl. Variability in non-coding DNA was examined in cattail (Typha latifolia) populations from five radioactively contaminated and 11 reference sites from Ukraine. There were 22 haplotypes observed in Chornobyl and reference populations, which had 10 and 21 haplotypes, respectively. There were no significant differences between Chornobyl and reference populations for the genetic diversity indices. Differences in observed heterozygosities between Chornobyl and reference populations were nearly significant with the higher values observed at the contaminated sites. There was no correlation between genetic and geographic distances among populations probably due to the high spatial heterogeneity, which was also indicated by a lack of phylogeographic structure. This level of heterogeneity made it difficult to document significant differences between Chornobyl and reference populations. The genetic variance partitioned among populations was very high (45%), but the variation detected between Chornobyl and reference populations was only 3%. The genetic differences were calculated for each individual from contaminated populations by comparing its sequence to a consensus sequence for the reference populations. The number of differences increased significantly with increasing concentrations of radiocesium and radiostrontium. The two most contaminated populations showed significantly higher numbers of individual genetic differences than the other contaminated populations. The correlation between individual genetic changes and the concentrations of radioactive isotopes in these individuals is evidence for a radiation effect on these plants. This effect is demonstrated within the contaminated populations and is in contrast to the lack of effect between contaminated and reference populations

Key words: genetic variation, chernobyl, radiation, Typha

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