On the Population Kinetics of the Root Meristem of Vicia faba Exposed to Continuous Irradiation

Abstract

The growth rate of bean roots was observed for several weeks under continuous irradiation at low dose rates; half of the roots were grown at 19[degree]C, the remainder at 12[degree]C. The intermitotic cycle time for roots grown at 19[degree]C is approximately half that for roots cultured at 12[degree]C; it was found that about twice the dose rate was required to produce a given reduction in growth rate for roots at the higher compared with lower temperature. These data support the hypothesis that it is dose per cell cycle that determines the degree of damage produced in a population of dividing cells exposed continuously to radiation.