Effect of ultraviolet radiation on physiological responses in the different varieties of radish (Raphanus sativus L.)

Ultraviolet radiation as one of important stressful environmental factors, has deleterious effects on plant physiological processes and growth. Plants confront with this conditions that produce ROS, via specific physiological mechanisms. This study to investigate the effect of UV-C radiation on the physiological responses in radish (Raphanus sativus L.cv), the plant with one year old and belong to brassicaceae . This experiment was conducted in a randomized complete blocks design with different three varieties of plant radish seeds that cultured hydroponically in green house. After two weeks, seedlings were treated with UV-C for a period of 10 days for 3 minutes / day with daily dose of 12KJ/m2. The results of the evaluation showed that in all studied variations, UV-C lead to reduction in shoot and root dry weight and leaf area. The radiation also reduced the photosynthetic pigments (chlorophyll a, chlorophyll b and total chlorophyll), sugar content and total soluble proteins. The total phenol, total amino acids and UV absorbing compounds such as anthocyanins and flavonoids, were increased under effect of UV-c radiation. By considering to obtained results, we concluded that in the variation of assayed metabolites, UV- C treated red radish plants had highest compatibility than other studied varieties.