| Boron effects upon gamma-ray and thermal neutron irradiations
in einkorn wheat S. MATSUMURA, T. MABUCHI and S. KONDO National Institute of Genetics, Misima, Japan As an approach to investigation of boron effects, seeds of Triticum monococcum flavescens soaked in water and 0.1, 0.5 and 1.0% aqueous solutions of borax for 2 days were exposed to gamma-rays in our institute and to thermal neutrons in the Japan Atomic Energy Research Institute's Nuclear Reactor, JRR-1. Gamma-irradiation with 137Cs was applied at the dosages of 0.5, 1, 2 and 3 kr. The thermal neutron flux was calculatec to be 5.2 x 109nth/cm2 - sec when the reactor was operated at 500 watts. The thermal neutron intergrated flux ranged from 1.3 to 10.4 x 1011nth/cm2 for 25-200 seconds. Gamma contamination dose rate was 117 r/min. The measurements of thermal neutron fluxes and gamma contamination dosages were made with the use of glass plates with different AgP03 concentrations. There was no marked difference in germination rate among gamma-irradiations of different dosages with different concentrations of borax. Only a slight decrease in germination rate was found in thermal neutron treatment at higher dosages, especially with high concentration of borax. The higher the dosage of gamma-rays and thermal neutrons and the concentration of borax, the more reduced was the growth of seedlings and the more increased were mitotic disturbances in the root tips after germination, as could have been expected. |