OLGA
V. TSYUSKO*, MICHAEL H. SMITH*, TARAS K. OLEKSYK†,
JULIA GORYANAYA‡
and TRAVIS C. GLENN*
*The
University of Georgia, Savannah River Ecology Laboratory, PO E, Aiken,
SC 29802, USA,
†Laboratory of Genomic Diversity, National Cancer Institute at
Frederick, NIH, Frederick, MD 21702, USA, ‡International Radioecology
Laboratory, Slavutich, Ukraine
Abstract
Research on populations from radioactively contaminated areas around
Chornobyl has produced ambiguous results for the presence of radiation
effects. More studies are needed to provide information on whether radiation
exposure at Chornobyl significantly affected genetic diversity in natural
populations of various taxa. Eleven and nine variable microsatellite
loci were used to test for differences in genetic diversity between
reference and Chornobyl populations of two cattail species (Typha angustifolia
and Typha latifolia, respectively) from Ukraine. Our purpose
was to determine whether radiation had a significant impact on genetic
diversities of the Chornobyl Typha populations, or if their
genetic composition might be better explained by species demography
and/or changes in population dynamics, mainly in sexual and asexual
reproduction. Populations closest to the reactor had increased genetic
diversities and high number of genets, which likely were due to factors
other than radiation including increased gene flow among Chornobyl populations,
enhanced sexual reproduction within populations, and/or origin of the
genets from seed bank. Both Typha species also demonstrated
small but significant effects associated with latitude, geographical
regions, and watersheds. Typha's demography in Ukraine possibly
varies with these three factors, and the small difference between Chornobyl
and reference populations of T. latifolia detected after partitioning
the total genetic variance between them is probably due primarily to
these factors. However, the positive correlations of several genetic
characteristics with radionuclide concentrations suggest that radiation
may have also affected genetics of Chornobyl Typha populations
but much less than was expected considering massive contamination of
the Chornobyl area.
Keywords
Chornobyl; genetic diversity; microsatellites; radiation; sexual and
asexual reproduction; Typha
Correspondence
Olga Tsyusko, Fax: 803 7253309; E-mail: tsyusko@srel.edu
SREL
Reprint #2970