Summary
The survival curves for Tradescantia clone 02 stamen hairs after X- and neutron-irradiation are characteristic for those usually found in many eukaryotic organisms. Two somatic mutations or aberrant cell types, pink and colourless, were closely associated with each other and followed similar dose–response curves after neutron irradiation until saturation doses were reached. This relationship changed at higher doses where one aberrant cell type predominates. Similar effects were found after X-irradiation but lethality was not observed at low doses. The yield of certain somatic aberrations within the possible spectrum changed at the doses at which stamen hair survival was reduced to about 70 per cent. The maximum yield of somatic aberrations in relation to the amount of lethality incurred may also be changed in this system by radiation quality.