Investigating the effect of priming with ascorbic acid on some germination and biochemical indexes of deteriorated sweet corn seeds

Introduction: Corn is one of the most important crops in the cereal family, and after wheat, it has the largest cultivated area in the world. Among the types of corn, sweet corn seeds are sensitive to storage conditions due to their low starch content and poor seed vigor. Therefore, it is essential to understand their physiological and biochemical behavior during storage to prolong their longevity and prevent the loss of vigor. On the other hand, seed deterioration is a natural phenomenon, resulting in seeds losing their viability and quality even under optimal storage conditions. This undesirable phenomenon causes more damage, especially in sensitive seeds such as sweet corn. Part of this damage is related to the decrease in the speed and percentage of seed germination, which leads to a decrease in plant density and failure to achieve the desired density in the field, resulting in decreased crop yield. This experiment evaluated and tested the ability of seed priming with ascorbic acid to improve damage caused by sweet corn seed deterioration.
Materials and methods: This experiment was carried out in the Laboratory of Seed Science and Technology, Faculty of Agriculture, Bu-Ali Sina University, as a factorial in a completely randomized design with four replications. The seed used for the experiment was Chase variety. Wheat seeds deteriorated by accelerated aging method for 72 hours at 43 °C. Then, the deteriorated seeds were primed at 25°C with 1, 1.5 ml of ascorbic acid and distilled water for 18 hours. The studied traits included germination percentage, mean germination time, germination rate, vigor index, malondialdehyde content, soluble sugars, soluble proteins, and superoxide dismutase enzyme activity.
Results: The results showed that vitamin priming of seeds with ascorbic acid improved the germination percentage, germination rate, vigor index, soluble sugars, soluble proteins, and activity of the antioxidant enzyme superoxide dismutase in deteriorated seeds. Among the examined traits, the mean germination time and malondialdehyde content of primed seeds decreased compared to non-primed ones. The concentrations of ascorbic acid used in mean germination time, germination rate, vigor index, and soluble sugars were not significantly different. However, it had a more favorable effect than hydropriming in improving the studied parameters of sweet corn seeds. While seed priming with a concentration of 1.5 mM ascorbic acid had the most significant effect on germination percentage, soluble proteins, malondialdehyde content, superoxide dismutase activity, and its difference with other priming treatments was significant. Even though seed priming with a concentration of 1.5 mM ascorbic acid had the greatest effect on the germination percentage, soluble proteins, malondialdehyde content, superoxide dismutase activity. However, its difference was significant from other priming treatments. It increased the percentage of germination, soluble proteins, and superoxide dismutase activity by 71, 85, and 44%, respectively, and decreased the content of malondialdehyde by 52.9%.
Conclusion: Based on the results from this experiment, it can be concluded that applying ascorbic acid, especially the concentration of 1.5 mM, as the best priming treatment is recommended to recover the lost quality of deteriorated sweet corn seeds and improve their germination characteristics.