|Budget Amount *help
¥3,600,000 (Direct Cost : ¥3,600,000)
Fiscal Year 1995 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1994 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1993 : ¥1,600,000 (Direct Cost : ¥1,600,000)
This study was carried out in 1993 to 1995 using the stamen hairs of Tradescantia, in order to investigate (1) the mutagenicities of alkylating agents and their synergistic effects with X rays, (2) the mutagenicity of maleic hydrazide (being used as herbicide) and its interactions with X rays, (3) the mutagenicities of air pollutants, and (4) variation of spontaneous mutation frequency, as well as to develop (5) a new testing system.
As for (1), the mutagenicities of ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS), dimethyl sulfate (DMS), N-ethyl-N-nitrosoures (ENU) and N-methl-N-nitrosourea (MNU) were determined, and EMS,MMS,DMS and MNU were confirmed to show clear synergistic effects with X rays. Concerning (2), maleic hydrazide (MH), a promutagen, was found to be activated into a mutagen in Tradescantia cells by peroxidase, and to act both antagonistically and synergistically with X rays when the activation of MH was inhibited and not inhibited by X rays, respectively. As for (3), treatments with nitrogen dioxide in nitrogen or air/nitrogen mixtures were conducted using a gas exposing chamber, but inconsistent results were obtained. The effect of ozone is now being investigated. About (4), a certain extent of variation in spontaneous mutation frequency due to temperature conditions was confirmed. Concerning (5), young inflorescence-bearing shoots with roots of clone BNL 4430 cultivated in the nutrient solution circulating growth chamber were found to be the most efficient materials for mutagenicity testings.