Radiosensitivity of rice seed in relation to water content and free radicals

Moisture content of seeds affects relative biological effectiveness of alpha particles but not protons in thermal neutron exposure

“…Sensitivity to gamma-rays and thermal neutrons after redrying of pre-soaked seeds It has been shown in barley (Caldecott 1955a, Ehrenberg 1955a, rice (Myttenaere et al 1965, Kawai and Sato 1966, Ukai 1969) and other crops (Katayama and Nagamatsu 1966) that, in the range of 2 to 25% of moisture content, seeds with an intermediate moisture content are most resistant to gamma-rays or X-rays and the radiosensitivity of seeds increased with decreasing or increasing moisture content. As shown in Table 1, D 50g for 0 μg·g −1 ( 10 B non-enriched) solution was lower in high moisture content Since the seeds of different moisture contents were placed in different layers during thermal neutron irradiation, doses of contaminating gamma-rays varied between moisture contents.…”

Factors modifying radiation induced stimulation in plants: Pre-irradiation seed moisture content

“…Firstly, it may be due to the difference in varietal response which has been noted by some authors [13,15]. At an enhanced moisture level (15%) no stimulation is discernible and the lower doses appear to be more damaging.…”

“…In the Cingalon variety it is reported to be between 10.6-13.2% moisture [2], in c.v. "Bluebonnet" 12-13% [6], in Norin-8 about 13% [10] and in 5 lowland varieties of USA between 14-16% [13]. In the Cingalon variety it is reported to be between 10.6-13.2% moisture [2], in c.v. "Bluebonnet" 12-13% [6], in Norin-8 about 13% [10] and in 5 lowland varieties of USA between 14-16% [13].…”

Plants and Radionuclides

“…This seems to reflect the preferential translocation of Ca to the above-ground organs of plants, although as the rate of transpiration of a plant decreases Ca transport appears to be diminished in favour of Sr movement. In relation to the highly mobile K and its analogue Cs, however, the absolute degree of internal translocation of both Sr and Ca is low with both elements existing largely as immobile complexes with glucuronic acids (Mortensen and Marcusiu, 1963) and pectates (Myttenaere and Masset, 1965).…”