X-Ray Effects on the Growth and Reproduction of Wheat

Abstract

IntroductionEvidences of miiodification and injury to plant parts are numerous in the extensive literature on the effects of x-ray treatment of plants. lists the effects produced on seventy species of flowering plants. Her work with wheat (3) shows that growing material is more strongly affected than non-growing by equal doses of radiation given in the same way. Seedlings from soaked grains given treatments of 1000 r-units and 5000 r-units made less growth in all respects than did controls, but showed inereased tillering. No flowering data were included.SHULL and MITCHELL (4) obtained deleterious effects when unfiltered radiations were used but the use of metallic screens, high voltage, low amperage, and brief exposures giving approximately 100 r-units, resulted in stimulative action on wheat, corn, oats, and sunflower seedlings. Twentyfour-hour-old wheat seedlings were irradiated with doses of x-rays varying from 565 to 13,560 r-units by FRANCIS (1). Retardation of fresh weight and dry weight production by the growing parts of the seedlings and retardation of linear growth of the coleoptile, the leaf, the primary root, and the lateral roots was obtained with all doses and time intervals employed. Respiration was likewise depressed with the exception of those seedlings which had received the smallest dose of radiation (565 r-units) and which were tested 5 or 6 hours after irradiation.The procedure of SHULL and MITCHELL was closely followed in an attempt to obtain further data on the stimulative effects of filtered x-radiation on growth, height, tillering, heading and flowering, green and dry weights, and moisture content of Marquis spring wheat. An attempt to determine the influence of age of seed on response to irradiation was made by the use of two samples of seed; one 57 months old (4 years, 9 months), the other 9 months old. A preliminary trial was made with Fulhio winter

The Effect of Ionizing Radiation on Plant Growth

“…Stimulated by these experiments, they obtained a patent in 1932, covering the use of shielded X radiation to increase the yields of crop plants. Wort (1941) found that wheat seeds irradiated with low doses of X rays produced larger plants than the controls.…”

X-ray Imaging

“…The abnormalities in the seedlings might have been caused by abnormal mitosis brought by the exposure to X-rays. Wort determined wheat kernels treated with 0.57-1.14 Gy exhibited accelerated growth rate; heading and flowering; increased fresh and dry weights irrespective of seeds age (9 and 57 mo) (Wort 1941). Alfalfa seeds treated at 107-638 Gy had delayed germination.…”

Comparison of the Developmental Response of Diploid and Tetraploid <i>Phalaris</i> Following Irradiation of the Dry Seed

“…Ratio of mean length of root/mean length of shoot per day Discussion: Reduction in growth with increasing doses has been reported by many investigators both in root and shoot at seedling stage, one (Bremer-Reinders, 1962) having worked on P. canariensis: but only in the present experiment has the initial stimulation of growth in the shoot of P, canariensis (2n) at 10 Krad been seen. The controversial topic of stimulation induced by radiation has been discussed in detail by Shull and Mitchell (1933), Wort (1941), Sax (1955) and Kaindall and Linser (1961). Recent reports on seed irradiation followed by stimulation include:-seedling height in wheat (Saric et al 1961); root and coleoptile of maize (Stein and Steffensen 1959), and increased phosphorylation in the corn root-tip (Cherry et al 1961).…”