Effects of gamma-radiation on DNA damage in onion (Allium cepa L.) seedlings

The effect of γ-radiation on the level of nuclear DNA damage in onion seedlings ( Allium -test) was studied using the comet assay. DNA breaks were first found in cells of onion seedlings exposed to low-dose radiation (≤ 0,1 Gy). Dose dependence of DNA damage parameters showed nonlinear behavior: a linear section in the low-dose region (below 0,1 Gy) and a dose-independent plateau in the dose range between 1 and 5 Gy. Thus, the comet assay can be used to estimate the biological effects of low-dose gamma-radiation on Allium cepa seedlings.