Germination Characteristics of Seeds of Maize (Zea mays L.) Exposed to Magnetic Fields under Accelerated Ageing Condition

Temperature and relative humidity in combination cause rapid decline in seed quality during storage. To maintain the seed quality in storage a number of physical and chemical treatments are used. Magnetic field treatment is one such physical treatment practiced to improve the seed quality. An experiment was conducted to investigate the efficacy of this treatment to improve the storability of seeds by subjecting the treated seeds to accelerated ageing conditions and periodically evaluating the deterioration. Our earlier experiments showed that exposure of fresh seeds of maize (Zea mays L) to specific static magnetic fields enhanced germination characteristics, field emergence traits and reduced seed leachate conductivity. In the present study, seed lots of maize (cv. Ganga Safed-1) were exposed to 100 mT for 2 h and 200 mT for 1 h respectively and subjected to accelerated ageing. Results showed that seed viability and vigour with days of artificial ageing was partially ameliorated in magnetically exposed seeds but showed significantly less reduction as compared to untreated controls. Similarly, magnetically treated seeds showed lower leachate conductivity than in unexposed control seeds during ageing. Ageing reduced the activities of antioxidant enzymes, viz., superoxide dismutase, catalase and peroxidase and level of soluble protein. However, seeds exposed to magnetic field maintained greater activity of these enzymes and higher levels of soluble proteins compared to untreated controls. Exposure of seeds to magnetic field reversed to some extent the deterioration caused by ageing as indicated by greater germination percent, seedling length and seedling dry weight than aged unexposed control.