| Plants of Azolla caroliniana were treated with different selenium concentrations (0, 1, 2, 5, 7, 10 ppm) for seven days. Selenium (Se) content in Azolla plants increased significantly with increasing Se concentrations in the culture media up to 5 ppm. This indicated that Azolla plants were a good accumulator for Se. Selenium accumulation determined changes in Azolla biomass, doubling time and relative growth rates. Treatment of Azolla plants with low concentrations of Se (1 ppm) resulted in a significant increase in biomass. This was accompanied by a reduction in hydrogen peroxide and malondialdehyde (MDA) contents; the decrease percentages were 78% and 60%, respectively at 1 ppm Se in comparison with the control. At higher Se concentrations (>5 ppm),... |
