X-RAY EFFECTS ON THE GROWTH AND REPRODUCTION OF WHEAT

Abstract

24-hr.-old seedlings of Marquis spring wheat grown from seeds 57 mos. old and 9 mos. old were irradiated by x-rays of 19 to 228 r-units, using a 1 mm. Al screen. Controls were plants receiving no treatment. Irrespective of the age of the seed greatest growth rate and height were produced by 114 r-unit treatments. Greatest fresh and dry wts. of plants grown from the older seeds resulted from the use of 76 r-units; of fresh seeds, from 57 r-units. X-radiation of from 76 to 114 r-units accelerated heading and flowering of plants grown from old seed by as much as 3 days, but retardation of heading and flowering occurred when fresh seed was irradiated. Height and wt. of Fulhio winter wheat seedlings were increased considerably by all doses of x-rays used, the maxima occurring when the dosage was 114 r-units.