Survival and dark germination of X-irradiated Arabidopsis Thaliana, race Estland

Abstract

Air-dry and presoaked (hydrated 10 hr on filter paper moistened with 10 −8 molar KNO 3) seeds of Arabidopsis thaliana, race Estland were exposed once to 250 KVP X-radiation; exposures ranged from 1 to 1000 Kr. Exposures of 150 and 60 Kr resulted in germination of only 50 per cent of the air-dry and presoaked seeds, respectively. No effect on the requirement of an exposure to light during germination was detected in any of the irradiated groups of X-1 seeds. The light requirement had apparently been fixed in the X-1 seeds prior to the time of irradiation; the genetic and somatic changes produced in the X-1 seeds by irradiation did not modify that requirement. Among the X-2 progeny of presoaked seeds exposed to 1–10 Kr, 14–20 per cent were light-indifferent. No mutants (light-indifferent) were detected among the X-2 progeny of seeds exposed to 1–20 Kr in an air-dry condition.