Cytogenetic Effect of Sulphur Dioxide on Vicia faba Plant I

抄録

The cytogenetic effect of fumigation of Vicia faba plants, with different concentrations of SO₂ (5-150ppm) for five hours and 5 ppm SO₂ for one, two and four successive days, has been investigated in the, PMCs, tetrads and PGs.
Fumigation with 5ppm SO₂ for a period of 5 hrs affected the induction of a highly significant percentage of abnormal PMCs/plant. Such effect increased proportionally as the concentration of the gas or the time of fumigation of the plants with SO₂ was increased.
Sulphur dioxide was effective in inducing abnormalities in the different meiotic stages, but the highest percentage of abnormalities was observed in the anaphase stages.
The common types of irregularities observed in the PMCs were: stickiness, lagging and disturbance of the chromosomes, sticky bridges, fragments, bridges with fragments and multipolar ana- and telophases. PMCs with more than one type of abnormalities were frequenctly observed. More than four spores were the dominant type of abnormalities observed in the quartet stage. A statistically significant percentage of nonviable PGs was observed in addition to the small and deformed PGs.
Taking chromosome fragmentation as the criterion for mutgenic potential, SO₂ has been found to be mutagenic, even after 5ppm fumigation for a period of 5 hrs.