بررسی اثر پرایمینگ با اسید اسکوربیک بر برخی شاخص های جوانه زنی و بیوشیمیایی بذرهای زوال یافته ذرت شیرین

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 vigour. Therefore, it is important to understand their physiological and biochemical behavior during storage to prolong their longevity and prevent the loss of vigour. On the other hand, seed deterioration is a natural phenomenon, as a result of which, seeds lose 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, failure to achieve the desired density in the field, as a result of which the yield of the crop decreases. In this experiment, the ability of seed priming with ascorbic acid to improve damage caused by sweet corn seed deterioration was evaluated and tested.

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 completely randomized design with four replications. The seed used for the experiment was Chase variety. Wheat seeds deteriorated by accelerated ageing 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, vigour 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 characteristics of germination percentage, germination rate, vigour 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, vigour index and soluble sugars were not significantly different from each other, but it had a more favorable effect than hydropriming in terms of improving the studied parameters of sweet corn seeds. While seed priming with a concentration of 1.5 mM ascorbic acid had the greatest effect on germination percentage, soluble proteins, malondialdehyde content and superoxide dismutase activity, and its difference with other priming treatments was significant. This was despite the fact that seed priming with a concentration of 1.5 mM ascorbic acid had the greatest effect on germination percentage, soluble proteins, malondialdehyde content and superoxide dismutase activity, and its difference with other priming treatments was significant. 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 obtained results from this experiment, it can be cocluded that the application of 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 its germination characteristics.