DIFFERENCES IN THE GENETIC RESULTS OF X IRRADIATION OF VARIOUS PLANT CELLS: STUDIES IN ARABIDOPSIS THALIANA (in German)
Various parts of the curciferous plant A. thaliana (Antwerp strain) were x irradiated: flower buds, flowers, pollen, and seeds. The X/sub 1/ generation grown from the irradiated seeds corresponded to the plants raised from the irradiated archespore cells, pollen, egg cells or zygotes. By natural self- pollination of these X/sub 1/ individuals, the X/sub 2/ and the following generations were obtained. The radiation effects were markedly different in the 5 types of cells investigated. The radiation dose that gave 20% surviving plants (as percent of the seeds of ovules treated), was 28.6 kr for pollen, 21.9 kr- for seeds, 5.4 kr for archespore cells, 5.1 kr for zygotes, and 2.5 kr for egg cells. Although these results might have been influenced by secondary selection mechanisms, some conclusions could be drawn regarding this varying sensitivity of the cells. In Arabidopsis it appears that diploid cells are more resistant than haploid, and that the compact nucleus of the pollen cell is more resistant than the more loosely structured nuclei of eggs or zygotes. In addition to this pattern of sensitivity, the cytogenetic effects of irradiating different types of cells suggest an influence of the nucleus status at the time of exposure. Thus nonhereditary malformations of rosette leaves in the X/sub 1/ generation of Arabidopsis appeared not only after irradiation of seeds but also after treatment of pollen. In the other three series, such X/sub 1/ deviations were lacking. Changes in the pollen nucleus must be one of the causes of the tissue degeneration. Likewise the fertility of the X/sub 1/ plants was diminished to differing degrees according to the kind of cell irradiated. A 20% dose applied to polien and seeds induced a degree of sterility several times higher than that caused in egg cells and zygotes by corresponding doses. Of the total induced gene mutations in the X/sub 2/ generation, only those were recorded that could be recognized in the seedling stage. The frequency of these mutations arising from the same dose (8 kr) corresponds with the structure of the irradiated nucleus in the opposite direction from the sensitivity values reported above. Moreover the mutart spectrum was different, depending on the stage of the irradiated plants. Based on the relatively large number of progenies tested (17,360), it was concluded that even the frequency of single gene mutations was divergent for the five stages investigated. (TCO)
- Research Organization:
- Universitat, Gottingen, Ger.
- NSA Number:
- NSA-17-035590
- OSTI ID:
- 4644499
- Journal Information:
- Z. Vererbungslehre, Vol. Vol: 93; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- German
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