Effects of gamma irradiation on radiation sensitivity in the diploid potato species Solanum chacoense

Abstract

The effect of ancestral exposure to radiation on the radiation sensitivity of progeny was tested the diploid potato species Solanum chacoense f. gibberulosum (Juz. and Buk.) Corr. Approximately 83 per cent of seedlings of a parental population that received 0 and 3 kR of gamma radiation survived and grew normally while only 26 per cent of those receiving 6 and 9 kR survived and appeared to grow normally. The survival and vigor of seedlings derived from plants that had survived these doses were compared following exposure to the same doses. The results indicated that radiation damage measured in terms of survival and vigor was increased following irradiation among most of those plants whose ancestors had received doses of 6 and 9 kR of radiation. This increase was attributed to the hereditary transmission of radiation-induced genetic damage in the form of recessive lethals and detrimentals. Certain lots failed to show increased radiation sensitivity as measured by decreased survival. This result was interpreted as resulting either from chance failure of mutation in the parental plants involved, or to somatic elimination of radiation damage induced in young seedlings.