Genotoxic Effects of Combined Effect of Pulsed Magnetic Field and Ionizing Radiation in the Meristem of Onion Seed Sprouts

In the present work, the sequential combined action of the pulsed magnetic field (PMF) (carrier frequency 1.8 MHz, modulated by pulses with a repetition rate of 28 kHz, magnetic field induction at the location of biological objects 75 mT per pulse with a duration of action on seeds of 60 s) and the amplitude of g-radiation at a dose of 3 g on the meristems of cells of the original onion. The systems of cells with chromosomal aberrations in the ana-telophase, types of aberrations, mechanisms of cells with micronuclei and the mitotic index were analyzed. Gamma radiation led to an increase in the frequency of cells with chromosomal aberrations by 12 times, the frequency of cells with micronuclei by 64 times. PMF led to an increase in the frequency of cells with chromosomal aberrations by 2 times, and cells with micronuclei by 3 times. The combined action of limiting factors was characterized by antagonistic interactions. Several hypotheses have been proposed to explain the effects of the combined action of IMF and gamma irradiation: IMF is guaranteed, leading to increased efficiency of DNA repair; IMF increases the level of apoptosis of lower cells and the elimination of radiation-induced aberrant cells; IMF leads to a more pronounced delay in the cell cycle and thus increases the time for repair of radiation-induced DNA damage.