THE COMBINED EFFECT OF IONIZING IRRADIATI ON AND HEAVY-METALS ON THE FREQUENCY OF CHROMOSOME-ABERRATIONS IN SPRING BARLEY LEAF MERISTEM

The results of a vegetative experiment on, the induction of genetic ef fects in barley intercalary meristem by the combined action of ionizin g irradiation and heavy metals are presented, it is shown that, while the induction of aberrant cells is equally dependent on the level of b oth factors, the degree of damage is determined mainly by heavy metals . Under the combined action of ionizing irradiation and soil contamina tion with cadmium, the type of nonlinearity is determined by the heavy metal (at low concentrations, synergistic effects occur; at high conc entrations, antagonistic effects take place). Under the combined effec t of ionizing irradiation and soil contamination with lead, irradiatio n dose plays the key role; low doses in combination with different con centrations of lead produce antagonistic effects; high doses, under th e same conditions, lead to synergistic effects. The data obtained indi cate that nonlinear effects induced by combinations of different facto rs should be taken into consideration in developing specifications con cerning the technogenic influence on agrocenoses.