Abstract
For the purpose to determine the sensitivity of mints to radiation, species of mints whose number of chromosomes and composition of genomes are known, were irradiated at the stages of seeds, rhizomes as well as growing plants and were examined radiation effects on their main physiological and morphological characters. As a result, it has been found that the interspecific difference of radiosensitivity was mainly due to the difference in composition of genomes and the sensitivity in allopoly-ploidies reveals no definitive tendency, but in the case of the artificial polyploidies the sensitivity tended to diminish along with an increase in number of chromosomes. It is asumed therefore, that the resistance potential of genomes against irradiation is in the order of A>R>S>J. The radiosensitivity of interspecific hybrids F1 lies generally intermediate to that of the parents, but when the sensitivity of the 'parents is relatively low, it becomes still lower than that of the parents, revealing the so-called heterosis phenomenon.
