pest resistance, changes in environmental adaptability, and variations in growth habit. Advantages of using Cobalt-60 gamma irradiation include few disposal problems, high reproducibility, good penetration in plant tissue, and the rate of mutation
This research tested the hypothesis that 60Co ionizing irradiation degrades polysomes to monosomes, a process that reduces growth of Pisum sativum seedlings. Dry and imbibed seeds and 5-day-old seedlings were exposed to 1.8, 3.6, 7.2, 14.4, or 28.8 krad of 60Co irradiation. Immediately after irradiation treatments, dry and imbibed seeds were planted, and later seedlings were harvested and analyzed. Five 1-cm root-tip samples from 5-day-old seedlings were crushed and layered onto 15% to 60% sucrose gradients and centrifuged for 55 min. The samples were processed through an ISCO ultraviolet chart maker. The monosome and polysome weights were read and analyzed. The monosome content was greater in the irradiated 5-day-old seedlings than in seedlings from dry and imbibed seeds. The growth of 5-day-old irradiated seedlings and seedlings from imbibed seeds was less than that of seedlings from dry seeds. The reduced growth of the irradiated seedlings suggests damage to the polysomes. When protein synthesis in plant cells is altered, perhaps through RNA decoding mechanisms, growth may be partially or completely arrested. Using sensitive plants to establish the injurious effects of ionizing irradiation on living organisms can educate and alert society to the detrimental effects of overexposure to irradiation such as that caused by nuclear accidents.
The quality of `Ron's Seedling', `American Bing', and `Lambert' sweet cherry drupes was not affected by irradiation doses up to 300 to 1000 gray. Peduncle discoloration increased in `Ron's Seedling' cherries when irradiated at 600 and 1000 gray. A dose of 75 gray prevented adult eclosion of more than 1300 Queensland fruit fly (Dacus tryoni, Froggatt). Larvae treated at the third instar were the least susceptible to gamma irradiation. The results indicated that gamma irradiation is a feasible quarantine treatment against D. tryoni without impairment to the quality of cherries.
Abstract
Two male sterile lines of cucumber (Cucumis sativus L.) were obtained from the inbred progeny of a single seed of the cv. Burpless Hybrid exposed to 16.000 rads from a cobalt-60 gamma source. The male steriles were characterized by abortion of the staminate blossoms. In rare instances where the flowers matured to anthesis, only rudimentary anthers, which contained no pollen, were present. Genetic studies showed that male sterility was due to a single, recessive allele common to both lines. This gene is designated ms2 - Cytological examination revealed that pollen abortion did not occur until after the mitotic division of the pollen grain nucleus. Sometime following this stage of development, the pollen grains and tissues of the anther degenerated and the staminate flowers aborted. One male sterile line also contained a reciprocal translocation induced by radiation, which was not linked with the male sterile character
of pollen wall have significant impacts on the success of pollination with irradiated pollen. Gamma rays obtained from Co 60 source are commonly used for pollen irradiation. When a flower is pollinated with irradiated pollen, the pollen’s vegetative
seed production in ‘Praline TM ’ (‘Tift H18’) and ‘Hush Puppy TM ’ (‘Tift PA5’) with cobalt 60 gamma radiation. Our objective was to use cobalt 60 gamma radiation to reduce seed production in P. alopecuroides genotypes with desirable ornamental
seed producing-genotype. Our objective was to use Cobalt 60 gamma radiation to reduce seed production in P. alopecuroides genotypes with desirable ornamental characteristics. ‘Tift H18’ (PP30724 P2) and ‘Tift PA5’ (PP31027 P2) are perennial P
produced by different seed companies to potentially include more genetic diversity among them. The rootstocks selected were Carnivor, Bs1, Tz148, Just, Rs841, Aq, Ercole, Cobalt, and Shintosa (for details on the rootstocks, refer to USDA-NIFA 2015 ; www
Florence and Sea Island Country Clubs ( Burton 1966b , 1991 ). Generating Variation from Radiation In 1970, the use of gamma rays from a cobalt-60 source to induce mutations in sterile triploid hybrids began as these lines could not be improved by
on NG and SG plants, whereas the Cucurbita hybrid ‘Cobalt’ resulted in significantly larger fruits (average, ± se , fruit weight 2960 ± 168.15 g vs. 2502 ± 60.94 g and 2578 ± 100.30 g in NG and SG melons, respectively) with a wider seed cavity (7