The effects of magnetic fields on growth and enzyme activities of Helianthus annuus L. seedlings. Maryam Peyvandi*, Neda Kazemi Khaledi, Sedighe Arbabian

In recent years, many research studies have been conducted on the effects of magnetic field on plants. But certain mechanisms regarding magnetic influences have not been defined yet. In this study, effects of magnetic fields (MF) on the growth parameters and enzyme activities of Helianthus annuus L. were investigated. Sterilized seeds in sterile conditions were exposed to 0, 0.5, 1 and 1.5 mT of MF. One day after the treatments percentage of seed germination was increased at 0.5 mT.  Different MF densities had no significant effects on root length and fresh weight of leaves. The highest level of shoot length was gained at 1 mT. In this treatment the activity of auxin oxidase was significantly decreased compared with that of the control samples. The activity of the catalase and peroxidase were decreased by MF. The minimum level of protein content and catalase and peroxidase activity were observed in the samples exposed to 1 mT of MF while there were no significant differences in the ascorbate peroxidase activity of different treatments. MF caused a reduction in chlorophyll a, b in all treatments compared to the control. The Results confirmed that the intensity of the MF had different effects on the growth parameters and enzyme activity.  Keywords: M. Peyvandi, N. Kazemi Khaledi and S. Arbabian. 2013. 'The effects of magnetic fields on growth and enzyme activities of Helianthus annuus L. seedlings'. Iranian Journal of Plant Physiology 3(3), 717-724.