Analyses of spontaneous pink mutant events in the stamen hairs of Tradescantia clone BNL 4430 cultivated in a nutrient solution circulating growth chamber

Further yearly analyses of spontaneous pink mutant events in the stamen hairs of Tradescantia clone BNL 4430 cultivated in the NSC growth chamber.

“…The present study was carried out in order to confirm and extend the results obtained by the previous 1-yearterm (December 12, 1998, through December 10, 1999 scorings and analyses of spontaneous pink mutant events (PMEs) in the stamen hairs of clone BNL 4430 cultivated in the NSC growth chamber (Ichikawa and Wushur, 2000). Namely, the seasonal variation in spontaneous somatic pink mutation frequency as well as the involvement of somatic recombinations in producing multiple and also single pink sectors in the stamen hairs found in the previous study were re-examined, because no such obvious seasonal variation had been observed in 1992-1995 in the NSC growth chamber , and also because the sectoring patterns of spontaneous PMEs in the stamen hairs of clone BNL 4430 were analyzed for the first time in the previous study (Ichikawa and Wushur, 2000). The scorings of spontaneous PMEs were therefore continued also for 52 weeks starting on December 11, 1999, on a slightly larger scale than in the previous year, and the sectoring patterns of all the PMEs detected were analyzed, differing from the previous study, in which only about 70% of the PMEs detected were analyzed (Ichikawa and Wushur, 2000).…”

“…The materials used. The young inflorescence-bearing shoots with roots of Tradescantia clone BNL 4430 described earlier (Shima and Ichikawa, 1994;Ichikawa and Wushur, 2000) were used. This clone is a diploid hybrid (2n = 12) between a blue-flowered T. hirsutiflora Bush and a pink-flowered T. subacaulis Bush (Emmerling-Thompson and Nawrocky, 1980), and thus is a blue/pink heterozygote.…”

“…The Tradescantia stamen-hair system, selected by the International Program on Plant Bioassays as one of the most suitable testers for detecting genotoxic hazards in the environment, has been used successfully to detect the genetic effects of ionizing radiations and various chemicals at low levels, as reviewed earlier (Underbrink et al, 1973;Ichikawa, 1981bIchikawa, , 1992Schairer and Sautkulis, 1982;Schairer et al, 1983;Ma et al, 1994). The system has also been shown to be suitable for studying the variation in spontaneous somatic mutation frequency (Takahashi and Ichikawa, 1976;Schairer and Sautkulis, 1982;Schairer et al, 1983;Ichikawa 1984Ichikawa , 1992Ichikawa , 1994Imai et al, 1991;Sanda-Kamigawara et al, 1991Ichikawa et al, 1995Ichikawa et al, , 1996aIchikawa et al, , 1996bIchikawa and Wushur, 2000). The use of the young inflorescencebearing shoots with roots of clone BNL 4430 cultivated in a recently developed nutrient solution circulating (NSC) growth chamber (Shima and Ichikawa, 1994;Ichikawa and Wushur, 2000) has been shown to be especially efficient for detecting mutagenic synergisms (Shima and Ichikawa, 1994Xiao and Ichikawa, 1995, 1996, 1998a, 1998b or antagonisms (Xiao and Ichikawa, 1995, 1996, 1998a, 1998c among various chemicals and X-rays, making it possible to determine spontaneous background mutation frequencies with higher accuracy than before Ichikawa and Wushur, 2000).…”

“…Namely, the seasonal variation in spontaneous somatic pink mutation frequency as well as the involvement of somatic recombinations in producing multiple and also single pink sectors in the stamen hairs found in the previous study were re-examined, because no such obvious seasonal variation had been observed in 1992-1995 in the NSC growth chamber , and also because the sectoring patterns of spontaneous PMEs in the stamen hairs of clone BNL 4430 were analyzed for the first time in the previous study (Ichikawa and Wushur, 2000). The scorings of spontaneous PMEs were therefore continued also for 52 weeks starting on December 11, 1999, on a slightly larger scale than in the previous year, and the sectoring patterns of all the PMEs detected were analyzed, differing from the previous study, in which only about 70% of the PMEs detected were analyzed (Ichikawa and Wushur, 2000).…”

The Mutagenic Potential Caused by the Emissions from Combustion of Crude Glycerin and Diesel Fuel

“…Therefore, it is possible to affirm that a pollutant that does not cause any detectable damage to the most sensitive species of plants would not affect other organisms, including humans (Guimarães et al 2000). The Tradescantia stamen hair (Trad-SH) assay has been one of the most appropriate tests to detect the genetic effects of the chemicals and ionizing radiation and to study the variations in the frequencies of spontaneous somatic mutations (Imai et al 1991;Ma et al 1994;Ichikawa and Wushur 2000). The assay is also highly efficient to determine the genotoxicity of liquid and gaseous environmental agents (Ma et al 1996;Mohammed and Ma 1999).…”