Effect of aging of seed and hydro-priming on germination characteristics and activity of some antioxidant enzymes of hybrid corn (Zea mays L.)

In order to investigate the effects of accelerated aging and hydro-priming of seed on germination and growth characteristics of corn seedling (cv. single cross 701), a factorial experiment was conducted based on completely randomized design with three replications in the research laboratory of University of Maragheh, Iran in 2015 year. Factors included three level of accelerated aging of seed (zero (control) and 2 and 4 days) and three level of pre-treatment of seed (Non-priming and hydro-priming for a period of 12 and 24 hours). The results of analysis of variance (ANOVA) showed that the simple effect of aging of seed and hydro-priming on all studied traits was significant at 1% probability level, but only the interaction of aging of seed and hydro-priming was significant on ascorbate peroxidase activity, electrolyte leakage rate, germination percent and germination rate. Simple and interaction effects of aging of seed and hydro-priming on the ratio of plumule to radicle were non-significant. The results of the mean comparison showed that all of the traits were reduced due to aging of seed. The soluble proteins contents, superoxide dismutase activity, plumule length, radicle length and seed vigor index due to seed aging of 2 days were 13.7, 10.9, 14.8, 14.8 and 33.2%, respectively, and due to seed aging of 4 days, they decreased by 36.8, 33.4, 32.4, 35.0 and 67.9%, respectively, relative to the control (without aging of seed). The results indicated that by increasing the duration of the hydro-priming of seeds from 12 to 24 hours, the soluble proteins contents, superoxide dismutase activity, plumule length, radicle length and seed vigor index were increased. Based on the results of interaction effects it was found that in the non-aged seed (control) applying hydro-priming for 24 hours was the highest and in the aged seeds (for 4 days), no hydro-priming had the least ascorbate peroxidase activity and percentage and germination rate. According to the results of this research, it can be stated that hydro-priming (especially for 24 hours) can decrease some of the destructive and minor effects of seed aging, and this technique can be used for reduction of the damage caused by the aging of corn seeds.