Influence of different intensities of magnetic field on germination, vegetative growth and some physiological aspects of salinity-stressed cucumber

Abstract

Two experiments were designed to investigate the effect of different static magnetic fields and 10% seawater stress on seed germination of cucumber (Cucumis sativus L. var. Beit Alpha), seedling vigour, vegetative growth and some biochemical aspects. Salinity stress reduced seeds germination, seedlings fresh mass and seedlings vigour by about 30%, 54%, and 70 % respectively. Moreover, salinity significantly reduced the depletion in seedling dry mass in comparison with control. The magnetic fields of 50 mT for ½ h and 100 mT for 30 s improved seed germination, seedlings fresh mass and seedlings vigour under salinity stress by about 30%, 50% and 150%, respectively in comparison with salinity treatment alone. Conversely, the dual treatment of 200 mT for 1/2 h and salinity stress had more reduction effect on cucumber than salinity alone. In general, the magnetic fields of 50 mT 30 s, 100 mT 1/2 h and 200 mT 30 s had a non significant effect on seed germination. Except for 50 mT 30 s intensity which had a promotive effect, the effect of all used magnetic fields on shoot biomass and chlorophylls content were comparable with those for seedlings fresh mass. The positive effect of magnetic fields seemed to be attributed to the enhancement in total amylase activity, soluble sugars, RNA, K+/Na+ ratio and chlorophylls level. On the contrary, magnetic treatments decreased peroxidase activity, total proteins and electrolytes leakage under salinity stress conditions. However, all magnetic intensities increased Fe content, in spite of being independent of magnetic intensity or exposure period.