ABSTRACT
PURPOSE: The purpose of this study was to assess the long-term effects of gamma-radiation, including low-dose radiation, on growth parameters of onion (Allium cepa) seedling roots 6-10 days after irradiation. MATERIALS AND METHODS: Onion seedlings were exposed to a 137Cs gamma source at doses ranging from 0.1 to 10 grays (Gy). Responses of root and shoot length growth were studied 6 and 10 days after irradiation. RESULTS: Our results showed inhibition of the root and shoot length growth 6 days after exposure at all doses, including the low dose - 0.1 Gy. At a later point in time (day 10), root and shoot inhibition was only observed after irradiation at high doses (above 5 Gy), and that suggested the occurrence of cell repair after irradiation at low doses. The results indicated that the length of seedling roots was more sensitive to gamma-irradiation than the shoot length. CONCLUSION: The results of the study suggested that short-term gamma-irradiation of onion seedlings (absorbed doses of 0.1-10 Gy) caused inhibition of plant growth 6 and 10 days after irradiation. The dose dependence of the onion root length was linear. The present study showed for the first time that short-term low-dose gamma-irradiation could induce long-term negative effects on plant growth.
