EFFECTS OF GAMMA-RAY IRRADIATION ON POLLEN. Thesis
The effect of gamma -irradiation on pollen germination, division of the generative nucleus, mitotic divisions within the embryo and endosperm, and fruit and seed sets was studied. Pollen of Solanum tuberosum var. AG 231 and diploid peony was irradiated at 1, 10, 20, and 40 kr, and that of Lilium regale and L. hybridum at 1, 2, 4, and 10 kr. The irradiated pollen was germinated on a liquid medium containing sucrose and boric acid. The results of germination indicated that pollen radiosensitivity is correlated to pollen size and chromosome number and size. L. regale and L. hybridum pollen was used for examination of the mitotic division of the generative nucleus in the pollen tube in vitro. All of the mitotic configrrations were abnomral following irradiation at 10 kr. Chromatid break, isochromatid break, and fragment were the main aberrations. On the basis of chromosome number, the % of aberrant chromosome increased as doses increased. The number of fragments per nucleus had no direct correlation with dosages. Chromatid breaks tended to increase with doses. The number of isochromatid breaks per 100 nuclei was much higher than that of chromatid breaks. The mitotic aberrations in the embryo and endosperm of potato following pollen irradiation included precocious or late movement of chromosomes at metaphase, bridges and fragments at anaphase, and increased ploidy. AG 231, L. regale, and L. henryi were used for fruit and seed sets following irradiation. Fruit size and seed sets declined with increased dosages. That required for impairment of seed set was usually lower than that required for fruit failure. The% of seed sets per fruit is in accordance with the% of normal mitoses leading to the formation of the male gametes. (M.P.G.)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-18-011802
- OSTI ID:
- 4106259
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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