Influence of oxygen at high pressure on the induction of damage in barley seeds by gamma radiation

Technical Report · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6509733

Donaldson, E; Nilan, R A; Konzak, C F

The influence of oxygen pressure prior to, during, and after irradiation on the induction of radiation damage was investigated using Himalaya (C.I. 620) barley seeds. Seeds were adjusted to water contents of 2 to 14% and then irradiated with /sup 60/Co gamma rays in vacuo or under various oxygen tensions. After irradiation, the seeds were rehydrated at approximately 0/sup 0/C in water continuously bubbled with oxygen or nitrogen. Biological effects of the treatments were recorded as M/sub 1/ seedling injury. Seeds irradiated in oxygen pressure sustained two or three times more damage than those irradiated in vacuo followed by rehydrating in oxygenated water. Greater damage occurred when seeds were (a) exposed to oxygen pressure and the pressure released before irradiation, (b) irradiated under oxygen pressure, or (c) irradiated in vacuo and then exposed to oxygen pressure than when irradiated in vacuo and rehydrated in oxygenated water. These results suggest that seeds can be saturated with oxygen before irradiation and also that the radiation-induced sites (presumably free radicals) which react with the oxygen are somewhat stable in very dry seeds. That the reaction probably occurs before the seeds are rehydrated was demonstrated by the failure to remove the effect of oxygen pressure between high oxygen pressure treatment and irradiation. The results indicate that placing the seeds under oxygen pressure may increase the rate and extent of the reactions occurring during post-radiation storage of seeds in the presence of oxygen. The increase in damage associated with aerobic rehydration is partially lost during aerobic storage and is largely pre-empted when seeds are placed under oxygen pressure. The decrease in damage associated with aerobic rehydration is accompanied by an increase in damage occurring with anaerobic rehydration, suggesting that the reaction which leads to damage was initiated before rehydration and to the same oxygen sensitive sites.

• Research Organization: Washington State Univ., Pullman (USA). Dept. of Agronomy and Soils
• OSTI ID: 6509733
• Report Number(s): RLO-2221-T2-37
• Country of Publication: United States
• Language: English

Related Subjects

560141* -- Radiation Effects on Plants-- Basic Studies-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BARLEY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CEREALS
COBALT 60
COBALT ISOTOPES
CRYOGENIC FLUIDS
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUIDS
GAMMA RADIATION
GRAMINEAE
GRASS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
IRRADIATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MEDIUM PRESSURE
MINUTES LIVING RADIOISOTOPES
MOISTURE
NONMETALS
NUCLEI
ODD-ODD NUCLEI
OXYGEN
OXYGEN ENHANCEMENT RATIO
PLANTS
PRESSURE DEPENDENCE
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RESPONSE MODIFYING FACTORS
SEEDS
YEARS LIVING RADIOISOTOPES