Abstract
This paper presents an experimental study on photosensitivity of tomato seeds subjected to non-equilibrium plasma produced by polarity reversed voltage pulses in ns range. Dielectric barrier discharge repeatedly propagates along the surface of the seeds on a glass barrier between plane-plane electrodes. After the discharge treatment, the seeds are incubated on a wet filter paper at 20℃ with dark-room condition for sciophilous plants or with irradiating condition for heliophilous plants. Regardless of the discharge treatment time (0, 5, 10, 20, 30 min), most part of the seeds starts to root within 4 days and then germinate within 1 week in dark-room condition. Both the leaf size and root length after 1 week incubation are not depend on the discharge treatment in dark-room condition. On the other hand, the seeds without discharge treatment have a lower ability for germination in irradiating condition because tomato is a heliophilous plant. However, the germination ratio of the seeds in irradiating condition increases with increasing the discharge treatment time. This interesting phenomenon implies that loss of sciophilous characteristics due to molecular structure change of photoreceptor in the seed coat is caused by the repetitive barrier discharges.
