EFFECT OF X RAY TREATMENT ON WHEAT SPECIES WITH DIFFERENT PLOIDY (in Italian)
Research carried out by Schwartz, Moutschen and others, on maize, barley and hexaploid wheat, has made evident the fact that some traits, after a point of maximum sensitivity to radiation (at different doses, according to the trait and the plant species studied) show a diminution of radiosensitivity which has been called reversal phenomenon.'' Schwartz has postulated that the point of maximum radiosensitivity at low doses can be attributed to chromosome breakage that induces death by aneuploidy, and the diminution of radiosensitivity nt high doses is caused by an inhibition of mitosis. With the goal of studying the behavior of species of different degrees of ploidy beionging to the same genus, three species of wheat, T. monococcum (diploid), T. durum (tetraploid), T. vulgare (hexaploid), were treated with x rays up to 240,000 r. The degree of humidity of the seeds at the time of radiation was 5% and 13%. It was possible to identify on the basis of the data obtained, the influence of the degree of ploidy, the degree of humidity, the trait considered on radiosensitivity in general, and on the manifestation of the reversal phenomenon.'' The results obtained show that the effects of high doses of ionizing radiations have a fairly complex determination. Examination of the behavior of certain characters such as the dry weight of the seedlings, which gives an indication of the metaboiic activity of the irradiated material, suggest that the reversal phenomenon'' might also include an inhibition of the autocatalytic activity (reduplication) of the hereditary material while the heterocatalytic activity (gene function) remain undamaged. At even higher doses this latter activity would also be inhibited and radiation death occurs. For greater clarity of the mechanisms of the effects of high doses of ionizing radiations, other experiments are planned which forsee the use of chemical and physical modification of radiosensitivity. (auth)
- Research Organization:
- Universita, Pavia, Italy
- NSA Number:
- NSA-17-010381
- OSTI ID:
- 4737636
- Journal Information:
- Atti Associazone Genetica Italiana (Italy), Vol. Vol: 5; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- Italian
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