Radioadaptive response of leaf meristem cells of inbred and heterosis Helianthus annuus L. plants during ontogenesis

The possibility of radioadaptive response (RAR) induction, its intensity and display in sunflower leaf meristem cells of hybrid and parental lines was studied. It was shown that induced radioresistance has developed in all studied forms. The intensity of the phenomena depends on the genetic state, the metabolic level and the period of ontogenesis. The increase of cell proliferation intensity is a necessary condition for RAR induction. In parental plants this increase is generated by adaptive preirradiation and in the hybrid ones it is a hybridization consequence.

Keywords: radioadaptive response (RAR), mitotic activity, hybrid, parental lines, ontogenesis