Radiological Study of Wheat Monosomics. I. Differential Sensitivity of Monosomic X and the Disomic to X-Irradiation.

M A N Y papers have been published on differential radiosensitivity due to polyploidy (see summary by SWAMINATHAN 1957) and sex (GLASS 1940; KAWAHARA 195 7). However, no systematic method of relating radiosensitivity to specific chromosome number has been devised. Aneuploid series, such as have been completed in Datura, Oenothera, maize, tomato, tobacco or wheat, facilitate studies relating change in radiosensitivity to the addition or removal of a specific chromosome. Differences in radiosensitivities between the aneuploids and disomics must be, directly and/or indirectly, attributed to the chromosome that varies in dosage in those strains. The experiment reported here was designed to study the effects that removing a specific chromosome had on the radiosensitivity of the wheat plant subjected to a wide range of X-ray dosages. Such a study should reveal comparative radiosensitivities for specific chromosomes.