The study of the effects of cytokinin and gibberellin on germination characteristics and antioxidant enzymes activity in deteriorated seeds of corn cultivars (Zea mays L.)

Deterioration of seed is one of the vigor reducing factors limiting seed germination. Determination of factors affecting seed deterioration is important. In order to determine the effect of plant hormones on germination characteristics and antioxidant enzymes activities of deteriorated corn seeds an experiment was carried out at seed and biotechnology laboratories of College of Agriculture, Tehran University in 2019. The study was designed with a factorial experiment based on completely randomized design (CRD) with four replications. The experiment treatments included varieties at 2 levels (704 single cross hybrid and 260 single cross hybrid), accelerated aging at 4 levels (0, 5, 10, and 15 day), and hormones at 2 levels (gibberellin and cytokinin). Seed deterioration reduced germination indexes and peroxidase and catalase enzymes activity. Treatment of deteriorated seeds with cytokinin and gibberellin increased antioxidant enzymes activities. Cytokinin was more effective than gibberellin in increasing the activities of antioxidant enzymes in deteriorated seeds. Results indicated that low seed vigor decreased the activity of enzymes and plant hormones as an agronomy solution compensated for the loss in low vigor seeds. Also, cultivar 704, with a higher vigor indicated amore enzyme activity than cultivar260.