Effects of Co 60 Gamma Irradiation on Corn Pollen

Abstract

Corn tassels were irradiated using Co 60 gamma rays at dose levels from 250 to 20,000 r. Twenty-four and forty-eight hours after irradiation the pollen was collected from the tassels and used to fertilize ears. The quantity of good seeds per ear, the germination percentage of these good seeds, and the seedling height 7 and 14 days later of the plants from these germinated seeds were recorded. No seeds were obtained beyond 4,000 r. There was little effect from pollen used 24 hours after treatment compared ivith pollen used 48 hours after treatment for any of the characters measured. There was a general dose response for number of good seeds per ear, and also in the percentage of germination of those seeds classified as good. The higher doses reduced both numbers of good seeds and their germination. There was no evident dose response of seedling height, if the seed did germinate it grew about as well as any at the dose levels measured.