| Abstract: | The effects of softer X-rays as an external agent on the developingembryos were manifested by a number of abnormalities such asenlargement and vacuolation of cells, disturbances in cell walls,disintegration of cells leading to the formation of cavities,disturbances in distribution of meristematic tissues, a numberof proliferations in different parts of the embryo, and retardedgrowth of the embryo during the early post-radiation period.In addition to these, deeply stained globular cytoplasmic bodieswere observed in radiated embryonic cells. Very similar kindsof abnormalities were produced by softer X-rays starting from400 r. and including 800 r. The frequency of occurrence anddegree of proliferations in embryos irradiated with 800 r.,however, were relatively higher than those produced by 400 r.and 500 r. Treatments with 300 r. units of irradiation inducedonly the appearance of deeply stained globular bodies withincytoplasm and no effects were visible with dosages below 300r. Comparative measurements of cell- lengths of the treatedand control embryos at undifferentiated as well as at differentiatedstages showed an increase in cell-lengths within radiated embryos.Radiated embryos showed defective pattern of germination. HarderX-rays were found to be less effective in inducing embryonicabnormalities than softer rays when equal calculated dosagesof the two were applied to the flowering spikes of Hordeum vulgareL. |
