effect of priming with ellagic acid, gibberellin and potassium nitrate on germination aspects of deterioration seeds of sweet corn (zea mays var. saccharata) of baisin variety

Introduction: sweet corn (zea mays l. var saccharata) is a genetically modified variety of common corn produced by a mutation in chromosome 4 (wang et al., 2022). such characteristics disrupt the vital capabilities of the seed and reduce the storage capacity of the seed. on the other hand, seed deterioration occurs with long-term storage even under controlled storage conditions and causes a decrease in germination potential and seedling root index (kapoor et al., 2010). some sweet corn cultivars, such as the basin variety, face problems due to weak germination characteristics to settle in the soil, and seed decay can further affect these characteristics and have a negative effect on it (revilla et al., 2021). with these explanations, increasing seed efficiency by using seed efficiency enhancing methods such as priming can facilitate the way to achieve better establishment of deteriorated seeds (ocvirk et al., 2021). research has shown that acid ellagic, gibberellin, and potassium nitrate increase germination by increasing alpha-amylase enzyme activity, auxin biosynthesis, and reducing growth-inhibiting substances such as abscisic acid (arab et al., 2022; saeedipour, 2022; rezai sokht abdani & ramezani, 2013). therefore, the aim of this research was to investigate the effect of priming with ellagic acid, gibberellin and potassium nitrate on the germination characteristics of the deteriorated seeds of sweet corn of the besin variety. materials and methods: an experiment was conducted in the form of a completely randomized design with four replications in yasouj university agronomy laboratory in 2024. the first factor of seed deteriorated at two levels (deteriorated and no deteriorated) and the second factor of seed priming at 8 levels (no priming, hydropriming, ellagic acid at two levels (25 and 100 mg/l), gibberellin at two levels (50 and 150 mg/l) and potassium nitrate at two levels (15 and 60 mg/l). to cause deterioration, 100 seeds were stored on metal nets in special containers with a temperature of 41±2 degrees celsius and a relative humidity of 95% for 24 hours, after which seed priming was done and after drying at room temperature, they were prepared for the standard germination test. 20 seed samples in each petri were placed in the germinator at 25 degrees celsius for 7 days based on the treatment levels and the number of germinated seeds were counted daily during the standard germination test. after the experiment, 10 seedlings were randomly selected from each petri dish and their root length, stem length and dry weight of root and stem were measured. finally, the indices of germination percentage, germination rate and seedling vigur index were calculated. statistical analysis and calculations were done using sas and excel software and mean comparison was done by lsd method at 5% level. results and discussion: the results of the analysis of variance show the significance of the effect of deterioration, priming and their interaction at the probability level of 1% on germination percentage, germination rate, root and shoot length, seedling length and weight vigor index of corn seeds (table 1). the results of mean comparing show the decrease of all investigated traits with deterioration. in the condition without deterioration + priming with 100 mg/l of ellagic acid, the highest germination percentage was achieved with an average of 70% (figure 1) and the highest germination rate with an average of 5.90 seed/day (figure 2). in conditions without deterioration of other hydropriming levels, gibberellin and potassium nitrate were ranked next. in the level without deterioration + priming with 100 mg/l of ellagic acid, the maximum root length (9.04 cm) was obtained (figure 3). the highest and lowest shoot lengths were obtained with the averages of 6.01 and 3.26 cm, respectively, from the levels without deterioration + priming with 25 mg/l of ellagic acid and deterioration seeds + priming with 25 mg/l of ellagic acid (figure 4). the highest seedling length vigor index (figure 5) and seedling weight vigor index (figure 6) (with 9.94 and 13.21, respectively) were obtained from the level without deterioration + priming with 100 mg/liter of ellagic acid and then the levels of 25 mg/l of ellagic acid, 150 and 50 mg/l of gibberellin and 15 mg/l of potassium nitrate were placed. in all traits, except the shoot length, the hydropriming treatment caused the lowest value in the deterioration condition. bayatian et al. (2021) stated that the reduction in germination characteristics is due to the interruption in the initiation of germination in the deteriorated seeds. deteriorated seeds need time to repair the damage done to the membrane and other parts of the cell and restart the activity of the antioxidant system. due to its antioxidant properties, ellagic acid may be effective in reducing the damage caused by lipid peroxidation due to seed deterioration, and the use of ellagic acid at the level of 100 mg/liter probably had a positive effect on germination characteristics by reducing the damage caused by oxidative stress (arab et al., 2022). priming with gibberellin increases the germination percentage and seedling length by increasing metabolites related to germination and faster root exit, and probably these factors have improved the characteristics related to germination in conditions of deterioration and without deterioration at the level of 100 mg/liter gibberellin (ghanbari & saeedipour, 2022). in the present experiment, it was found that priming with 15 mg/liter of potassium nitrate had the highest indicators related to germination, which probably increased auxin biosynthesis at these levels, and with the beginning of embryo growth and the decrease of abscisic acid, the percentage of germination and seedling length increased (rezai sokht abdani & ramezani, 2013). conclusion: considering the superiority of the level of 100 mg/l of ellagic acid in terms of the length and weight of the seedling, it seems that priming is recommended to achieve the germination percentage and proper establishment in basin variety. also, the results showed that according to the results of most of the examined traits, the use of gibberellin and potassium nitrate can also increase the characteristics related to germination in conditions of deterioration. references arab, s., baradaran, firouzabadi, m., gholami, a. & haydari, m. 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