Study of pulsed laser beams and magnetic field on radish seeds

Abstract

In this work we report a study on the influence of innovative pulsed stresses utilizing an UV laser and a homemade generator of magnetic field on radish seeds (Raphanus sativus L.) growth. We analysed the seed germination and seedling growth. The UV pulsed laser was an excimer KrF operating at 248 nm, 23 ns of pulse duration, with a laser fluence of about 40 mJ/cm2. The generator of pulsed magnetic field was realized by the electric discharge on a coil of a high voltage capacitor of 150 μF, 60 kV . The magnetic field pulse waveform exhibited damped oscillations at 215 kHz with a maximum intensity of 400 mT . Groups of uniform radish seeds were exposed to laser pulses at five different doses: 30000 shots (KrF/1), 80000 shots (KrF/2), 145000 shots (KrF/3), 225000 shots (KrF/4) and 275000 shots (KrF/5). Other groups were exposed to magnetic field at eight different doses: 3600 shots (MF/1), 7200 shots (MF/2), 10800 shots (MF/3), 14400 shots (MF/4), 18000 shots (MF/5), 21600 shots (MF/6), 32400 kshots (MF/7) and 36000 shots (MF/8). Simultaneously, untreated seeds were used as control. All treatments were performed at room temperature. Both untreated and treated seeds were transferred in Petri dishes and followed for their germination and seedling growth up to 96 h. The results showed that the stress induced by UV laser photons brought a significant stimulation on root growth which may contribute to improve the performance and the productivity of the plants. On the contrary, all physical stresses induced by magnetic fields did not have effect on seed germination, as well as on cell elongation growth and on hypocotyls in comparison to control seeds.