Iranian Journal of Seed Research

Seed quality is one of the most important factors affecting seed germination and seedling growth. In order to investigate the effects of seed aging on germination and seedling growth of sunflower cultivars, a factorial experiment was conducted based on a completely randomized design with three replications in seed research laboratory of Shirvan Higher Education Complex. To create 7 different treatments of seed aging, seeds of three cultivars Ghasem, Farrokh and Barzgar (as the first factor) were kept at a high temperature (43◦ C) and high relative humidity (100%) for 0 (control), 24, 48, 72, 96, 120 and 144 hours (as a second factor). The results of mean comparison showed that germination percentage, rate and seedling growth of Farrokh cultivar was more than other cultivars in each aging level. Germination percentage, rate and uniformity, seedling dry weight, radicle and stem length reduced linearly with increase in the duration aging in all cultivars. Under the aging conditions, the time to beginning and ending of germination was significantly increased. Overall, it was concluded that seed quality of sunflower cultivars was seriously decreased under the aging conditions.

This study was conducted to evaluate the effect of hydropriming and seed aging on germination and enzymatic properties of pinto bean under salinity stress as factorial based on a completely randomized design with four replications. Two groups of seeds (i.e., non-aged and aged seeds), two hydropriming treatments (i.e., hydro primed and unprimed seeds) and six salinity treatments (i.e., 0, 2, 4, 6, 8 and 10 dS/m) were the experimental factors. The results showed that the highest mean time and percentage of germination, plumule length and vigor were observed in the control (i.e., distilled water) and hydropriming treatments. Maximum root length and percentage of seedling water were obtained in the control (i.e., distilled water) and aged seed treatments. In addition, in terms of radicle dry weight, the highest amount was observed in salinity of 4 dS/m and non-aged hydro primed seeds. The highest plumule dry weight was observed in salinity of 6 dS/m and allometric index in salinity of 8 dS/m for non-aged seed and aged seed without hydropriming, respectively. An increase in the levels of salinity stress and aging the seeds increased the malondialdehyde and reduced the activity of germination, mean time and germination percentage, and seedling growth. Seed hydropriming reduced the peroxidation of the cell membrane and generally improved the speed and uniformity of germination, aged and natural seeds vigor under both salinity and optimum conditions. As a result, hydropriming can increase the tolerance of bean seeds to salinity at the germination stage and increase the germination capacity of stored seeds for cultivation.

Extended abstract
Introduction: A wide range of deteriorative conditions (especially moisture content and temperature) may affect seed quality during storage which may lead to seed aging. As the most important component of the phenylpropanoids pathway, trans-cinnamic acid, found abundantly in plants and its endogenous levels is influenced by stress conditions. The present study was conducted to investigate germination features, seed reserve mobilization, electrolyte leakage and malondialdehyde content in aged cowpea seeds affected by different concentrations of cinnamic acid.
Materials and Methods: The research has been performed in the laboratory of Faculty of Agriculture, Shahrood University of Technology, Iran. The experiment was designed as a factorial (two factors of the experiment included two levels of seed quality including non-aged and aged seeds and five levels of cinnamic acid concentrations including 0, 15, 30, 45 and 60 µM) based on a completely randomized design. Accelerated aging was applied as an efficient method to mimic storage conditions in the presence of accelerating factors. Cowpea (Vigna unguiculata) seeds (Bastam local variety) were incubated in a relative humidity of 95% and a temperature of 43 °C for 72 h to accelerate aging. Both seed lots were treated with 5 different concentrations of cinnamic acid for 6 h followed by standard germination and vigor tests. Data of germination and vigor tests were processed using the GERMINATOR software. Heterotrophic growth, seed reserves mobilization, electrical conductivity and membrane lipid peroxidation were assessed using the available methods.
Results: In this study, cowpea seeds responded to cinnamic acid differently based on their primary quality. In deteriorated seeds, concentrations of 45 µM and 60 µM could successfully enhance seed germination percentage, as compared with the aged seeds (i.e., control). A concentration of 45 µM also improved the vigor of deteriorated seeds. Seed pretreatment of 15, 30 and 45 µM enhanced seed reserves utilization in non-aged seeds. Aging negatively affected area under curve, germination uniformity and seedling dry weight of the deteriorated seeds. Application of 30 µM cinnamic acid improved germination uniformity. The area under the curve was positively affected by 15µM and 30µM. Concentrations of 45 µM and 60 µM enhanced seedling dry weight. Applying 45 µM cinnamic acid decreased electrolyte leakage by 38% and improved efficiency of seed reserves mobilization. Moreover, seed malondialdehyde content, as an indication of membrane lipid peroxidation, showed a sharp decline by applying increased concentrations of cinnamic acid.  
Conclusions: Based on our results, cowpea seeds respond to cinnamic acid differently based on their primary quality. These results imply that seed pretreatment with 45 µM cinnamic acid may successfully invigorate aged cowpea seeds. We also conclude that cinnamic acid application cannot improve physiological traits and can be regarded as a potent antioxidant in the invigoration of the aged seeds.
 
Highlights:

1. This is the first study focusing on the role of cinnamic acid in alleviating deterioration in aged seeds.
2. Cinnamic acid has been introduced as a robust antioxidant, which is effective in reducing the deleterious effects of seed deterioration.

Extended Abstract
Introduction: Soybean (Glycine max (L.) Merrill) is the primary source of vegetable oil. Even in desirable conditions, soybean seeds lose their viability in long term storage. Many factors contribute to seed deterioration, including genetic factors, mechanical damage, relative humidity, storage temperature, seed moisture content, existence of microflora, and seed maturity, which reduce seed quality and make seeds unfit for cultivation purposes.
Materials and Methods: In order to investigate the effects of seed deterioration on seed germination and also the effects of salicylic acid and ethylene on the improvement of deteriorated seeds of G. max., accelerated aging test for 0, 6 and 10 days and natural aging test for 6 months were conducted. After aging conditions, seeds were imbibed with 50 µM salicylic acid and 10 µM ACC (precursor of ethylene) for 6 hours at 25 °C. In addition, after natural and accelerated aging tests, a bunch of seeds was used without any hormonal treatment (i.e., dry seeds) as control seeds. The seeds’ germination percentage, total sugar, fructose, and glucose were investigated. Moreover, the gene expression of GAI1 and LOX1 was measured on dry seeds and under imbibition of water, salicylic acid and ACC at 6, 12 hours using Q-RT-PCR method.
Results: The germination results showed that increasing number of aging days led to a decrease in germination. Total sugar content in seeds aged for 6 days did not have a significant difference, as compared with non-aged seeds. However, total sugar content in seeds aged for 10 days was significantly higher than non-aged seeds. Increasing accelerated aging levels from 0 days to 10 days led to increases in glucose and fructose contents in dry seeds. In addition, genes exhibited different expressions in different days and hours. Increasing aging from 0 days to 10 days led to increases in GAI1 gene expression. Moreover, LOX2 expression increased in accelerated aging from 0 to 6 days. LOX2 gene expression in naturally dried aged seeds also increased and was higher than that in non-aged seeds. SA and ACC had different effects on measured values.
Conclusion: In general, it can be concluded that the deterioration of seed quality and vigor result from numerous degradation processes and disruption in seeds’ physiological activity. This study showed that aging is associated with an increase in total sugar, glucose and fructose levels. In addition, the expression of the genes involved in the germination is also affected. Increases in LOX2 gene expression were observed in both accelerated aging and natural aging pathways. GAI1 gene expression increased in accelerated aging. However, in normal aging, it decreased.
 

Highlights:

1. Identifying the role of LOX2 and GAL1 genes in soybean seed deterioration.
2. Investigating seeds’ physiological responses under natural and laboratory aging conditions.

Extended abstract
Introduction: Seed deterioration is a physiological phenomenon that affects all germination, biochemical, cytological, and growth characteristics of plants. So it is necessary to use seed vigor enhancement methods to resolve these problems. One of these methods is the application of seed priming techniques to reduce deterioration effects. Therefore, the present study aimed to investigate the effect of different pre-treatments by using Nano-zinc, ascorbic acid, humic acid, gibberellin and KNO₃ on germination indices and chromosomal aberration of aged onion seeds.
Material and Methods: This experiment was performed as factorial based on a completely randomized design with 3 replications (100 seeds per replicate) in the faculty of agriculture at Urmia University. The first factor was the level of aging at 4 levels (control, 12h, 24h, and 48h) and the second factor was seed pre-treatments at 6 levels (control, Nano-zinc (30 mg), ascorbic acid (100 mg), humic acid (150 mg), gibberellin (200 mg/l) and KNO₃ (0.1%). Given that the germination was not similar at different levels of aging, the seeds were germinated at control and 12h of aging after 6 days, at 24 and 48h of aging after 8 and 9 days, respectively. Hence, germination percentage, germination rate, normal seedling, mean germination time, and seed vigor were evaluated after the mentioned times. Chromosomal aberrations were also examined.
Results and Discussion: The results showed that the interaction effect of aging and seed pre-treatments on germination indices were significant at %1 probability level. By increasing the period of aging, all germination characters decreased significantly. The highest germination percentage (80%, 70%, 50%) and germination rate (5.350, 3. 316, 1.525 seed/day) were obtained by using Nano-zinc At 12h, 24h and 48h ageing levels. Nano-zinc and gibberellin had the highest effect on seedling vigor and normal seedlings. Seedling vigor increased significantly by using Nano-zinc and gibberellin at 12h (1133, 933.9), 24h (742.9, 692), and 48h (369.9, 323.3). The chromosomal aberration was reduced by using pre-treatment.
Conclusion: In this study, the most effective pre-treatments to improve germination characteristics and reduce chromosomal aberrations were gibberellin (200 mg/l) and Nano-zinc (30 mg). Therefore, it can be stated that the use of Nano-zinc and gibberellin as seed pre-treatments can significantly reduce the effects of deterioration on onion seeds.

Highlights:
1- Nano-Zinc and gibberellin were the most effective priming treatments on seed germination and growth characteristics of the aged onion seeds.
2- Priming treatment reduced the percentage of chromosomal aberration in the onion and the highest effect was obtained using Nano-zinc and gibberellin.

Extended Abstract
Introduction: Seed germination and seedling emergence depend on the genetics of plant species and are also influenced by environmental factors. Genetics and nutritional status of the maternal plant, maturity stage at a time of harvest, and environmental factors such as temperature, salinity, drought, and soil fertility influence seed germination. Seed vigor as the main parameter of seed quality decreases due to accelerated aging and storage. The objective of this study was to evaluate the response of accelerated aged Chia seed to different levels of salinity stress.
Material and Methods: Two-way factorial experiment with experimental factors, including five levels of seed accelerated aging durations (0, 24, 48, 72, 96 h) and six levels of salinity stress (0, 50, 100, 150, 200, and 250 mM) was arranged based on a complete randomized block design with three replications. The experiment was conducted at seed technology laboratory Khuzestan Agricultural Sciences and Natural Resources, University of Khuzestan, in 2019.
Results: Results of analysis of variance revealed that the effect of seed accelerating aging, salinity stress, and interaction effects of both factors on all measured germination traits were significant (p<0.01). The best pattern of seed germination was evaluated using three-parameter sigmoid models (logistic, Gompertz, and sigmoidal) and two polynomial models (quadratic and cubic), then the performance of all models was compared using (R²_adj), root square of the mean (RMSE) and corrected Akaike index (AICc). Results showed that at accelerated aging duration, models' performance to describe Chia seed germination response varied at different levels of salinity stress. At no aging and 72h of accelerated aging treatments, the sigmoidal model exhibited the best fit on final seed germination, whereas for the other levels of accelerated aging, Gompertz exhibited the best fit. Based on the output of the sigmoidal model, for no aging and 72 hours of accelerated aging, 50% of seed germination was declined at 171.7 and 76.9 mM, respectively, and based on the results of the Gompertz model, after 24 and 48 h of accelerated aging, seed germination declined to 50% at 163.8 and 129.6 mM. Results obtained from fitting polynomial models on seed germination showed that the cubic model provides reasonable descriptions for studied traits such as seed vigor.
Conclusion: Chia seed germination was sensitive to salinity and accelerated aging treatments. At no aging condition, Chia seeds tolerate salinity stress up to 200 mM and were able to germinate. By increasing aging durations, seed germination declined dramatically at all salinity levels and after 96 hours of aging, there was no seed germination at 150 mM.

 
Highlights:
1- The best nonlinear model to study accelerated Chia seed response to salinity stress was selected using the model selection criterion.
2- Chia seed germination threshold to salinity stress was determined for not- aged and aged seeds.

Extended abstract
Introduction: Seed deterioration is associated with oxidative stress and uncontrolled accumulation of reactive oxygen species. Seeds have a group of enzymatic and non-enzymatic antioxidants that protect them against reactive oxygen species and help maintain seed vigor and support seed germination processes. The response of different cultivars to seed deterioration is different. Knowledge about the sources and mechanisms of deterioration and how different cultivars respond can help to select the appropriate cultivar for the region and also provide useful information in selecting and applying appropriate management methods for storage and increasing the storage time of seeds.
Materials and Methods: The Experiment was conducted as factorial based on a completely randomized block design with three replications. Treatments included one and six months of natural storage (4˚C, 11 percent moisture content of seeds and 60% RH) and accelerated aging (96 hours at 45˚C and 100% RH) applied on four cultivars including Hashemi, Gilaneh, Khazar and Domsiyah. Germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity, catalase (CAT), peroxidase (POX), superoxide dismutase (SOD) activity, malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content were evaluated.
Results: The results showed that accelerated ageing and storage of seeds for six months led to reduced germination percentage, germination rate, shoot length, radicle length, shoot dry weight, radicle dry weight, shoot vigor index (SVI), α-amylase activity reduced in all four cultivars. This decrease was accompanied by an increase in the free radical content of MDA and H₂O₂ and a decrease in the activity of the antioxidant enzymes SOD and POX. Malondialdehyde content was lower in the seeds stored for six months. The activity of CAT increased after deterioration treatment, this increase was more intense in the seeds stored for six months. These seeds also showed lower H₂O₂ content compared to accelerated aging seeds. Khazar cultivar showed lower H₂O₂ content as a result of higher CAT enzyme activity. Moreover, this cultivar showed better germination percentage and germination rate after deterioration treatment compared to other cultivars. The decrease in germination percentage due to deterioration in Domsiyah was very severe. This cultivar showed the lowest germination percentage, germination rate, seed vigor and α-amylase activity in the accelerated aging treatment. Gilaneh and Hashemi cultivars showed higher germinability, α-amylase activity and SOD and POX at the beginning of the experiment, but after deterioration treatment, their germinability decreased along with the activity of antioxidant enzymes.
Conclusions: In all studied cultivars, the accelerated aging and storage of seeds for six months adversely affected germination rate. This decrease was accompanied by an increase in free radicals in the seeds and a decrease in the activity of antioxidant enzymes SOD and POX, which were less severe in Khazar cultivar and more severe in Domsiyah cultivar. These results indicate the greater importance of the storage conditions in Domsiyah cultivar.

Highlights:
1- The effect of storage and seed deterioration on the activity of antioxidant enzymes, reactive oxygen species and seed germination in rice was investigated.
2- The results of accelerated aging test and natural aging were compared for a better conclusion about the response of the cultivars.
3- The two improved cultivars were compared with two local cultivars (with high cultivation area).

Extended abstract
Introduction: Due to the high sensitivity of seeds to damage caused by diseases or environmental stresses, germination is considered an important stage in the plant life cycle: Germination, its uniformity and emergence decline during storage due to seed vigor deterioration. Moisture stress is one of the important environmental factors affecting germination, especially during improper storage. Seed priming with gibberellic acid improves seedling characteristics in different plants under different environmental conditions. Therefore, this research aims to investigate the effect of gibberellic acid and seed deterioration on germination indices and antioxidant enzymes of safflower seeds (Carthamus tinctorius L.) under water stress conditions.

Materials and Methods: In order to investigate the effect of gibberellic acid on germination indicators and changes in antioxidant enzymes of aged safflower seeds under osmotic stress conditions, a factorial experiment was conducted in the form of a completely randomized design with four replications. The first factor includes three osmotic stress levels: zero (control), -0.4, and -0.8 MPa, the second factor includes nine aging levels (zero, 1, 2, 3, 4, 5, 6, 7, and 8 days of aging). at a temperature of 41 degrees Celsius) and the third factor included seed priming treatment at three control levels (non-priming), zero (hydro-priming), and priming with 50 mg/l gibberellic acid. A 3-parametric sigmoid model was used to show the changes in germination indices at different levels of seed deterioration.

Results: The effect of osmotic stress, seed deterioration, and seed priming on the measured indices such as germination percentage, germination rate, seedling dry weight, normal seedling percentage, seedling length, seed germ, catalase, and ascorbate peroxidase, as well as seed protein were significant so that the measured indicators decreased with increasing seed deterioration and moisture stress. The results showed that the highest measured germination indices were obtained from seed treatment with 50 mg/l gibberellic acid under normal osmosis and non-deterioration conditions. Also, seed priming with gibberellic acid treatment caused an increase in catalase, ascorbate peroxidase, and protein activity compared to non-primed seeds under deterioration and non-deterioration conditions.

Conclusion: Results showed that the most suitable prime level used was gibberellic acid 50 mg/l, which had acceptable results under both stress conditions and normal conditions and deterioration and non-deterioration in comparison with other treatments. Therefore, the use of gibberellic acid hormone can help to improve germination indices as a result of changes in biochemical activities.

Highlights:

1. The effect of accelerated aging and priming on safflower seed germination under moisture stress conditions was investigated.
2.The effect of priming on catalase and peroxidase activity of aged safflower seeds was investigated.

Extended abstract
Introduction: Soybean is among the most important oil crops of the world. Currently, 55% of the world's oil is supplied by soybean. Seed aging, an undesirable feature of agriculture, is one of the main problems in agriculture that leads to economic losses. Although aging is an irreversible process, its speed is delayed by proper storage and optimal storage methods. While kept under inappropriate conditions after harvesting, its quality during storage declines. Priming has a direct and indirect effect on the growth and development of plants, and its indirect effects are more beneficial than its direct effects. Priming improves the longevity of low-vigor seeds. During the priming of these seeds, a long time can occur to repair metabolic damage before any progress in germination, which ultimately prevents further deterioration. Several studies have shown that seed treatment with sodium nitroprusside during reaction with reactive oxygen species and increased activity of antioxidant enzymes is essential to protecting plants against stress. The aim of this study was to the investigate the effect of sodium nitroprusside levels on germination indices and antioxidant enzyme activity in soybean seedlings under accelerated aging test.
Materials and Methods: This experiment was conducted in 2023 as a factorial in the form of a completely randomized design with 3 replications at the University of Mohaghegh Ardabili. Experimental treatments included accelerated aging treatment at three levels (0, 24, and 48 hours) and three levels of sodium nitroprusside (0, 100, and 200 ppm).
Results: The results showed that aging reduced germination indices including germination percentage (GP), germination value (GV), and mean daily germination (MDG). Also, priming with different levels of sodium nitroprusside, especially the 200 ppm level, improved these traits, but priming with sodium nitroprusside decreased the mean germination rate (MGR) and the mean germination time (MGT). The superoxide dismutase and ascorbate peroxidase enzyme activity due to priming with sodium nitroprusside 200 ppm compared to the control showed an increase of 22 and 26%, respectively. Also, the content of peroxidase enzyme activity showed an increase of about 34% compared to the control in priming with sodium nitroprusside 200 ppm and 48 hours aging compared to the control. The lowest catalase enzyme (7.7 units mg protein^-1 min^-1) was in pretreatment with sodium nitroprusside 100 ppm and without aging.
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with sodium nitroprusside 200 ppm may be considered an effective way to improve germination indices and antioxidant enzymes activity of soybean and can be used as a treatment to deal with salinity conditions in soybean seedlings and improve their growth.

Highlights:

1. Seed priming using sodium nitroprusside improved germination indices of seed common soybean under aging.
2. Priming with sodium nitroprusside increased antioxidant enzyme activity.
3. The concentration of 200 ppm sodium nitroprusside showed a better effect on germination indices and biochemical characteristics.

Extended abstract
Introduction: Deterioration reduces the quality of seeds. Oilseeds like Nigella are highly susceptible to seed aging. Seed priming enhances the quality of deteriorated seeds by improving germination indices and increasing the activity of antioxidant enzymes. This research aimed to investigate the extent of damage caused by accelerated aging treatment on the germination characteristics and antioxidant enzyme activity of Nigella seeds and the possibility of mitigating the adverse effects of aging through hormonal priming with cytokinin.
Materials and methods: This research was carried out in the form of a completely random basic design with four replications in the seed technology laboratory of Khuzestan University of Agricultural Sciences and Natural Resources in 2017. The treatments included hormonal priming with cytokinin at five levels (0 (control), 10, 20, 40, and 80 m/l) for two durations (12 and 24 hours), and aging under 100% relative humidity and a temperature of 45 °C at five levels (no aging, 24, 48, 72, and 96 h).
Results: The analysis of variance results indicated that germination indices were only influenced by main and two-way effects at the 5% and 1% probability levels, while the three-way interactions, including aging, hormone concentration, and priming duration, were significant for plant growth and longitudinal and weight indices at the 1% probability level. Furthermore, it was evident that the priming treatment mitigated the negative effects of aging, with the concentration of 10 milligrams per liter of cytokinin for a duration of 12 h having the most significant impact among the hormone concentrations used on the measured traits. The highest germination percentage (88%) and the lowest germination percentage (63.33%) were observed at concentrations of 10 and 80 mg/l, respectively. The use of cytokinin at optimal concentration improved catalase activity and protein levels. The results showed that in the control conditions, the activity of the catalase enzyme was 0.76 units per mg of protein and the amount of protein was 0.51 mg/g, which reached 0.97 units per mg of protein and 0.79 mg/g with seed priming.
Conclusion: Based on the results obtained from this research, aging led to a reduction in germination indices, the activity of antioxidant enzymes, and seed protein content. The best treatment applied was cytokinin hormone priming for aged Nigella seeds at a concentration of 10 mg/l for 12 h. According to the results, the application of cytokinin at its optimal concentration (10 mg/l) improved the catalase enzyme activity and protein content. Therefore, it can be suggested that hormonal priming with cytokinin helps mitigate the adverse effects of aging in Nigella plants.

Highlights:

1. The impact of hormonal priming with cytokinin at concentrations of 10, 20, 40, and 80 mg/L on aged Nigella seeds was investigated.
2. The use of a concentration of 10 mg/l of cytokinin hormone for 12 hours was introduced as the best treatment.
3. Cytokinin was introduced as a significant hormone that enhances the activity of antioxidant enzymes and physiological traits in aged Nigella seeds.

Extended abstract
Introduction: Production of high-quality seeds is a major concern in the agriculture industry. The lifespan of a seed, which can extend over several decades, is essential for safeguarding the plant's genetic resources. Storage conditions, including seed moisture level, relative humidity, gases (such as oxygen, nitrogen, and carbon dioxide), and temperature, are the primary factors that determine seed lifespan. Among these aging treatment, oxygen has the most detrimental effect on seed germination, storage metabolic activities, and enzyme activity of dried seeds. Lalemantia iberica and Lallemantia royleana seeds contain high levels of fatty acids, especially linolenic acid (56-67%), which have significant beneficial effects on health. However, a large number of L. iberica and L. royleana seeds deteriorate due to inadequate storage conditions by most farmers. The aim of this study is to investigate the effects of different storage conditions, especially natural and controlled aging, aging with oxygen, and nitrogen on germination, chemical activities, metabolic reserves, and enzymatic activities of dry L. iberica and L. royleana seeds.
Materials and Methods: A factorial experiment based on a completely randomized design with four replications was carried out in the seed science laboratory at the Faculty of Agriculture, Shahid University in 2021. The experimental treatments included storage environments (control, natural aging, controlled aging, and aging with oxygen and nitrogen pressure) and plant species (Lallemantia iberica and Lallemantia royleana).
Results: The results indicated that aging with oxygen had the most detrimental impact on the germination rate, seed germination, reservoirs content, and the activity of alpha and beta amylase enzymes, compared with controlled and natural aging in both species. Conversely, the highest levels of electrical conductivity, hydrogen peroxide, lipid peroxidation, and saturated and unsaturated fatty acids were observed in dry seeds stored under oxygen aging conditions. In comparison to artificial aging (controlled aging and oxygen aging), seeds stored under natural aging conditions exhibited the highest germination rate, storage compound content, and α amylase enzyme activity. Throughout the storage process, it was observed that the deterioration rate was higher in the dry seeds of L. iberica compared with L. royleana.
Conclusions: Aging with oxygen can be regarded as a rapid artificial aging method for assessing the longevity of dry seeds. Conversely, the use of low temperature and humidity conditions in natural aging can be considered a practical method for preserving the quality and longevity of seeds. Due to their high content of storage compounds (sucrose, starch, and total sugar content), L. royleana seeds can be stored for extended periods.

Highlights:

1. Seed aging led to an increase in biochemical indices such as lipid peroxidation, hydrogen peroxide, and saturated and unsaturated fatty acids.
2. The rate of deterioration in dry seeds of L. iberica was higher than those of L. royleana.
3. The content of storage compounds and the activity of amylase enzymes were higher in L. royleana seeds compared with L. iberica.

Extended abstract
Introduction: In order to improve seed germination under environmental stress conditions such as salinity, one of the solutions is to use seed priming. Despite this advantage of priming, the longevity of primed seeds usually decreases and it has been observed that using post-priming treatments such as heat shock can improve the longevity of primed seeds. This research investigates the effect of seed priming with salicylic acid, methyl jasmonate, and brassinosteroid under salinity stress and the effect of heat shock after priming on improving the longevity of primed seeds.
Materials and Methods: The effect of seed priming with hormonal substances such as methyl jasmonate at three concentrations of 1, 100, and 1000 micromolar and brassinosteroid at three concentrations of 25, 75, and 100 mg/liter on increasing the seed germination traits of Suaeda fruticosa was investigated under salinity stress during separate experiments. In both studied hormones, priming temperatures of 5, 10, and 15°C were used for 1 and 2 days. Hormonal seed priming with salicylic acid at a concentration of 25 mg L^-1 for 2 days at 10°C -obtained from the previous results (unpublished)- was used for comparison with those of the studied treatments. To determine the most suitable accelerated aging stress for evaluating and determining the best heat shock treatment, the accelerated aging test of seeds was carried out for two, four, six, eight, and ten days. In this research, to improve the longevity of primed seeds, they were exposed to heat shock treatment at temperatures of 30, 35, and 40°C for 1, 2, 3, and 4 hours after seed priming.
Results: Both seed priming treatments with methyl jasmonate and brassinosteroid significantly increased all the tested germination traits compared to the control (without priming). This increase in traits such as germination percentage, vigor index, and seedling length in seed priming with methyl jasmonate was 46.4%, 67%, and 41%, respectively, and in the case of priming with brassinosteroid was 32%, 44%, and 38%, respectively. Also, in this research, the heat shock treatment at 40°C for four hours after priming had a significant and positive effect on seed germination. Application of the mentioned treatment increased germination by 60% at the end of the aging period compared with the control (without the application of heat shock).
Conclusions: Despite the significant increase in germination percentage by each of the hormonal substances like methyl jasmonate and brassinosteroid, the comparison of the best treatment combination of these substances with salicylic acid showed that seed priming with 25 mg L^-1  of salicylic acid for two days at 10°C caused a significant increase in the percentage of germination under salinity stress. Also, the heat-shock post-priming treatment significantly improved the longevity of primed seeds.

Highlights:

1. Seed priming significantly increases the seed germination characteristics of the Forssk plant against high salinity stress.
2. As the aging period increases, the primed seeds experience a significant drop in germination compared with the control.
3. Heat shock immediately after priming can significantly increase the longevity of primed seeds compared with the control.