Effect of Soil Organic Matter Content and Ammonium Perrhenate(186Re) on the Growth of Chinese Cabbage and Radish

This study investigates the effects of different concentrations of the radioactive nuclide rhenium (Re) and soil organic matter content on the growth, dry matter production, and chlorophyll content of Chinese cabbage (Brassica rapa subsp.pekinensis) and radish (Raphanus sativus).Ammonium perrhenate (NH 4 ReO 4 ) was utilized as a substitute for the radioactive isotope 186 Re, a fission product, and was incorporated into the soil at various concentrations of 0, 5, 10, 20 mgkg -1 to analyze its impact.For Chinese cabbage, a significant reduction in growth parameters (number of leaves, leaf area, leaf length, leaf width, plant height, and root length) was observed as the concentration of Re increased.Notably, at concentrations of 20 mgkg -1 and higher, there were marked decreases in both fresh and dry weights.This trend persisted throughout the 80-day growth period, indicating that higher Re concentrations significantly inhibited the growth of Chinese cabbage.In contrast, soil organic matter content did not substantially affect the growth parameters of Chinese cabbage.Similarly, in radish, increasing Re concentrations resulted in a marked reduction in growth, with significant decreases in fresh and dry weight observed at the 80-day growth stage.Chlorophyll content analysis revealed a declining trend in both Chinese cabbage and radish as the Re concentration increased, suggesting a detrimental effect of Re on photosynthesis.These results experimentally demonstrate the effects of radionuclides on plants and are expected to provide basic information on radiation exposure.