IRANIAN JOURNAL OF SEED RESEARCH
Year:2020 | Volume:6 | Issue:2|Papers Count:12

Introduction: Salinity is one of the most serious abiotic stresses, causing instability in germination and seed emergence due to low osmotic potential and ionic toxicity. Development of simple and low-cost biologic methods is essential for short-term management of salt stress. The use of plant growth-promoting rhizobacteria increases the rate and uniformity of germination. This research aimed to investigate the effect of bacterial growth-promoting bacteria on the germination and seedling growth indices of alfalfa c. v. Hamedani in different salinity levels. Materials and Methods: A CRD factorial experiment with four replications was conducted in Seed Science and Technology Laboratory of Shahrekord University in 2016. The first factor consisted of 6 salinity levels 0, 2. 5, 5, 7. 5, 10 and 12. 5 dS/m created with sodium chloride, and the second was four levels of bacterial pre-treatment: no inoculation with bacteria and biopriming, inoculation of alfalfa seeds with Acinetrobacter calcoaceticus PTCC 1318, Bacillus megaterium PTCC 1250 and Enterobacter aerogenes PTCC 1221. The seeds were treated with bacteria and placed at a 20 ° C growth chamber. They were then irrigated with desired solutions depending on the salinity treatment. Germinated seeds were counted daily and the parameters of germination percentage and rate, seedling length, seedling dry weight, vigour index I, II and allometric coefficient were calculated after 10 days. Results: Salinity levels higher than 10 dS/m reduced germination indices and seedling growth of alfalfa. The highest reductions were obtained for 12. 5 ds/m salinity level versus control for germination percentage (10. 81%), germination rate (49. 48%), plumule and radicle length (13. 30% and 28. 88% respectively) and vigor index I and II, which were 30. 27% and 6. 28%, respectively. The seed treated with A. calcoaceticus was able to tolerate salinity stresses more than others. For example, the reduction for the seed treated with A. calcoaceticus was only 4%, compared with non-stressed control. In salinity conditions 2. 5 and 5 dS/m, the highest rate of germination was obtained, using A. calcoaceticus bacteria. In addition, the seeds treated with E. aerogenes showed higher stability at different levels of salinity for seedling length traits. The highest vigour index related to the use of A. calcoaceticus in salinity was 7. 5 ds/m. Conclusions: A. calcoaceticus had a significant role in reducing the negative effects of salinity on germination percentage and rate, vigour index I and II and allometric coefficient while E. aerogenes bacteria were more effective in reducing negative effects of salinity on seedling length and dry weight.

Introduction: Seed dormancy, as a technique to avoid environmental stress, is important in preserving plant species and could be of various types including physiological, physical, morphological and morphphysiological dormancy. Seed testa hardness is one of the main causes of dormancy in leguminous family plants. A common method for breaking seed dormancy in leguminous plants is the use of scarification treatments. Given that oxygen deficiency is a factor that induces dormancy, scarification treatments through acceleration of gas exchanges, especially oxygen and carbon dioxide, can reduce seed dormancy and finally increase germination percentages. In addition, priming with gibberellic acid can help dormancy breaking in plant species that have physiological dormancy, finally leading to germination. Therefore, the present study investigated seed dormancy and germination to find the most appropriate treatment for the elimination of seed dormancy in three ecotypes of Astragalus cyclophyllus. Materials and Methods: A factorial experiment based on a completely randomized design with three replications was carried out at Agriculture Laboratory of Lorestan University in 2013. The first factor was three ecotypes of Astragalus Semirom, Damavand and Zanjan, and the second factor was seed dormancy breaking treatments. The applied treatments were: control, (mechanical scarification plus chilling time with 10, 20 and 30 days prechilling at 4° C, mechanical scarification + gibberellic acid at concentrations of 400 and 500 ppm for 48 hours, scarification with sulfuric acid 96% for 2 and 4 min, mechanical scarification and 2% potassium nitrate for 72 h, mechanical scarification and gibberellic acid 400 ppm for 48 h and 20 days prechilling. The measured indices included germination percentage, mean germination time, seedling length, seedling fresh weight, seedling dry weight and alpha-amylase activity. Results: The results showed that the interactions between seed dormancy breaking treatments and ecotype were significant for all the traits. Based on the results of mean comparison, Damavand ecotype exhibited better performance in terms of most of the traits studied, as compared with Semirom and Zanjan ecotypes. Compared with the treatments applied, mechanical scarification plus gibberellic acid 400 ppm was more effective in germination parameters and seedling vigor index. Mechanical scarification and gibberellic acid 400 ppm for 48 h along with 20 days prechilling increased total germination percentage by an average of 67. 68% in Semirom ecotype and was more effective in increasing the activity of α-amylase enzyme. Conclusion: It seems that seed dormancy of Astragalus cyclophyllus is not of physiological type and increased germination can be due to mechanical scarification in physical dormancy breaking and priming effect of prechilling and gibberellic acid.

Introduction: Conditional dormancy (CD) is a dynamic state between dormancy (D) and nondormancy (ND). Seeds at the conditional dormancy stage germinate over a narrower range of temporal conditions. Conditional dormancy is usually observed in seeds with physiological dormancy. However, primary conditional dormancy has also been seen in some freshly harvested seeds. The purpose of the present study was to investigate whether freshly harvested oilseeds have non-dormancy or conditional dormancy. Materials and Methods: A factorial experiment was conducted based on a completely randomized design with four replications at Seed Technology Laboratory of Aburaihan Campus, University of Tehran, Iran, in 2018. In this experiment, seeds of rapeseed were collected from 20 different locations in Golestan and Mazandaran provinces. Following that, a germination test was carried out at different temperatures (5, 15, 20, 30, 35° C), and the germination percentage and seed germination rate were recorded. In order to break seed dormancy, two treatments were used: gibberellic acid and after-ripening. For after-ripening treatment, seeds were stored in a paper bag in a dry and dark environment for 6 months. For gibberellic acid treatment, a solution of 100 parts per million (PPM) of gibberellic acid was prepared and added to the Petri dishes. Subsequently, the percentage and rate of germination were recorded. Results: The results showed that freshly harvested seeds had primary conditional dormancy and germinated in a narrow range of temporal conditions. In addition, cardinal temperatures for freshly harvested seeds were 4. 45 and 27. 8 for bases and ceilings, respectively. Following gibberellic acid and after-ripening treatments, seeds germinated in a wider range of temperatures and base and ceiling temperatures reached 1. 74 and about 40° C, respectively. Thus, germination percentage of seeds treated with gibberellic acid and after-ripening increased at both high and low temperatures. However, the increase in germination percentage was higher at high temperatures than low temperatures. In addition, the effect of gibberellic acid treatment was more than that of after-ripening treatment on the release of dormancy, and after-ripening treatment had an intermediate effect between the gibberellic acid and freshly harvested seeds. Conclusion: Based on the results of this experiment, the application of gibberellic acid and after-ripening treatments resulted in breaking the dormancy of freshly harvested seeds and increased germination temperature range at high and low temperatures. Of the two treatments, gibberellic acid had the greatest effect on breaking dormancy and increasing temperature range. Among the cultivars, these changes were maximum in the germination capacity of Hyola 50 and Trapar cultivars and Trapar cultivar had minimum changes.

Introduction: Priming is one of the most commonly used seed enhancement techniques. Events such as increased synthesis of nucleic acids, activation of repair processes, increased respiratory activity, and improved antioxidant capacity during priming lead to advanced metabolism in seeds. The most important effects of priming include increased percentage, speed and uniformity of germination and emergence. However, the longevity of primed seeds in storage is the major concern for researchers as it restricts widespread use of this technique. Some researchers believe that priming reduces the storage capacity of seeds, while others have reported increased seed shelf life after using priming treatments. Therefore, this study sought to investigate the effects of priming on the storage capacity of the seeds of canola cultivars under different storage conditions. Material and Methods: In this study, the effects of priming on the shelf life of seeds of three canola cultivars including Dk-xpower, Traper and Hayola50 were investigated. For this purpose, the seeds were first treated with hydropriming and osmopriming methods. Then primed and control seeds with 6, 9, 12 and 15% moisture content were stored for 8 months at 15, 25, 35 and 45 ° C. Sampling from different seed treatments was carried out at intervals of 1 to 30 days to assess germination. Finally, by fitting a three-parameter logistic model to cumulative germination data versus the day after storage, the time to germination loss to 50% was calculated and used to compare seed storage behavior between the treatments. Results: The results showed that the storage behavior of canola seed varies greatly depending on the cultivar, and each cultivar showed a distinct behavior. Priming effects on the shelf life of seeds were different depending on the storage conditions, cultivars and also the priming methods. Comparison of the effects of priming on the seeds’ shelf life under different storage conditions showed that priming treatments were more efficient under higher seed moisture content and storage temperatures than those with lower seed moisture content and storage temperatures. In addition, priming treatments in Dk-xpower cultivar often increased the seeds’ shelf life. However, in the Traper and Hayola 50 cultivars, hydropriming often improved the seeds’ shelf life, and in contrast to osmopriming, it led to a decrease in the shelf life of the seeds. Conclusion: Based on the results of this study, it was shown that priming effects on canola seed viability can be a function of various factors such as cultivar, storage conditions, and also the type of priming treatment. Moreover, in this study, hydropriming often increased seed longevity whereas osmopriming often increased the deterioration rate and reduced seed longevity.

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 μ M salicylic acid and 10 μ M 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.

Introduction: Management of agricultural operations in sugarcane fields should be informed by the accurate knowledge of sugarcane growth stages and phenology and is to be reviewed based on variety differences. Given the importance of emergence stage on the establishment of seedling and final quality and quantity of sugarcane yield and given the absence of respective information, a study was conducted to investigate the effect of different planting dates on the phenological characteristics of the seedling stage of sugarcane cultivars in the south of Khuzestan Province during 2016-17 and 2017-18. Materials and Methods: The experiment was carried out as a randomized complete block design with three replications. In terms of growth period length, Very premature, Premature, and Semi mature cultivars included CP73-21, CP57-614 and CP69-1062. Planting dates were Aug. 11th, Aug. 23rd, Sep. 1st and Sep 11th. Planting operation was conducted manually and with 1/3 overlap of grafts. In order to prevent the negative effects brought about by the dispersion and non-uniformity of the experimental field and the special conditions of sugarcane cultivation, each cultivar was cultivated in a separate field and after sampling and the study of different traits, the statistical analysis of each cultivar was performed separately. Results: The results showed that sugarcane seedling was not affected by annual conditions and the interaction effect of annual conditions and planting dates. The significant differences of planting dates were observed at the beginning of emergence, its completion and rate of emergence and the number of leaves produced and their area. The fastest rate of the beginning and the completion of emergence was obtained in CP73-21, and on different planting dates, it was more permanent than other cultivars studied, while CP69-1062 had the slowest and more behavioral diversity of emergence on different planting dates. The cultivar CP73-21 did not produce good results in terms of leaf area, but the CP69-1062 cultivar was able to produce the highest level of leaf area due to the extra number of leaves and the mean value of a single leaf area. In addition, the best results were obtained in all characteristics in August, followed by September. Conclusions: Based on the results, in order to achieve the best emergence of sugarcane buds, it is necessary to complete the cultivation of most of the fields within the first twenty days of the beginning of the planting season and priority should be given to cultivar CP69-1062 and then cultivars CP57-614 and CP73-21. Due to the differences between sugarcane cultivars, utilizing seedling stage growth data can lead to more scientific management of the crops in terms of the characteristics of each cultivar, which eventually leads to desirable yields.

Introduction: The effect of environmental factors on the developmental stages of a plant causes the planting date to vary from one region to another. Temperature is a very important factor in the maximum percentage germination and germination rate. Priming improves germination rate, brings about the uniformity of germination and reduces seed susceptibility to environmental factors. The purposes of this experiment were to study the effects of priming treatments at different temperatures on the germination characteristics of Hibiscus sabdariffa under laboratory conditions, to investigate priming treatments on different planting dates and to compare early planting dates on the farms. Materials and Methods: The experimental study was carried out as a factorial experiment in a completely randomized design with four replications in the Laboratory of Seed Technology of Kashmar University Jihad. The first factor is five primings (Concentrations of ZnSO4 (10 mM), Humic acid (2. 5 cc) and the combination of Humic acid and Zinc sulfate, Biological materials (Pota Barvar 2), no treatment (control) and the second factor is five levels of temperature: 10, 12, 14, 16 and 18 ° C. Field studies were carried out in Agricultural and Natural Resources Research Center of Kashmar in three separate experiments in 2018. The research was carried out in a completely randomized block design with three replications on three planting dates (March 25th, April 15th, and May 4th, 2018). In each experiment, priming treatments were applied similarly to field experiments. Results: The results of the current experimental study showed that temperature, priming and temperature interaction with priming had a significant effect on all the traits studied. The highest percentage and rate of germination were observed at 18 ° C and priming with Pota Barvar 2. The results also showed that planting date had a significant effect on all the traits studied in the field experiment. Priming showed a significant difference only in stem fresh weight. The interaction effect of priming and planting date was not significant for the traits studied. The highest germination percentage was obtained on April 15’ s planting date. By planting later than March 25 to 15 April, a decrease of 74% was observed in the rate of germination. Among priming treatments, the combination of Zinc Sulfate and Humic acid showed a significant superiority, compared with other treatments. Conclusion: The findigns suggest that due to the high sensitivity of seed germination of sour tea at low temperatures, the planting date in each area should be carefully chosen so that it does not coincide with temperatures below 18 ° C.

Introduction: Temperature is one of the primary environmental regulators of seed germination. Seed priming technique has been known as a challenge to improving germination and seedling emergence under different environmental stresses. Quantification of germination response to temperature and priming is possible, using non-liner regression models. Therefore, the objective of this study was to evaluate the effect of temperature and priming on germination and determination of cardinal temperatures (base, optimum and maximum) of Brassica napus L. Material and Methods: Treatments included priming levels (non-priming, priming with water, gibberellin 50 and 100 mg/l) and temperature (5, 10, 15, 20, 30, 35 and 40 ° C). Germination percentage and time to 50% maximum seed germination of Brassica napus L. were calculated for different temperatures and priming by fitting 3-parameter logistic functions to cumulative germination data. For the purpose of quantifying the response of germination rate to temperature, use was made of 3 nonlinear regression models (segmented, dent-like and beta). The root mean square of errors (RMSE), coefficient of determination (R2), CV and SE for the relationship between the observed and the predicted germination percentage were used to compare the models and select the superior model from among the methods employed. Results: The results indicated that temperature and priming were effective in both germination percentage and germination rate. In addition, the results showed that germination percentage and rate increase with increasing temperature to the optimum level and using priming. As for the comparison of the 3 models, according to the root mean square of errors (RMSE) of germination time, the coefficient of determination (R2), CV and SE, the best model for the determination of cardinal temperatures of Brassica napus L. for non-primed seeds was the segmented model. For hydro-priming and hormone-priming with 50 mg/l GA, the best models were segmented and dent-like models and for hormone-priming with 100 mg/l GA, the dent-like model was the best. The results showed that for non-priming, hydropriming with water, gibberellin 50 and 100 mg/l treatments, the segmented model estimated base temperature as 3. 54, 2. 57, 2. 34 and 2. 34 ° C and dent-model estimated base temperature as 3. 34, 2. 45, 2. 21 and 2. 83 ° C, respectively. The segmented model estimated optimum temperature as 24. 62, 23. 23, 23. 69 and 24. 38 ° C. The dent-model estimated lower limit of optimum temperature and upper limit of optimum temperature as 20. 01, 19. 62, 16. 25, 19. 87 and 28. 81, 27. 38, 29. 58 and 27. 31 ° C. Conclusion: Utilizing non-liner models (segmented, dent-like and beta) for quantification of germination of Brassica napus L. response to different temperatures and priming produced desirable results. Therefore, utilizing the output of these models at different temperatures can be useful in the prediction of germination rate in different treatments.

Introduction: Stevia (Stevia rebaudiana Bert. ) is a herbaceous perennial plant that belongs to the family of Asteraceae. Stevia is a self-incompatible herb and the seeds resulting from this plant have low germination ability. Steviol glycosides found in this plant are 250-300 times sweeter than sucrose and despite their sweet flavor; they are not absorbed by the body. In general, the poor germination capacity of Stevia seeds is a major impediment for its large-scale cultivation. Priming is one of the seed enhancement techniques that could lead to an increase of germination percentage and germination rate under stress conditions. Therefore, the present study was conducted to evaluate the impact of priming with salicylic acid (SA), iron (Fe) and zinc (Zn) on some germination indices, seedling growth as well as the content of photosynthetic pigments in Stevia under normal and drought stress conditions. Materials and methods: A factorial experiment using a completely randomized design was carried out in the Seed Science and Technology Laboratory of Agricultural College, Shahed University, in 2017. The factors studied comprised four levels of drought stress (0, – 0. 3, – 0. 6 and – 0. 9 MPa) and seven priming combinations with SA, Fe and Zn. Non-primed seeds (dry seeds) were also considered as control. In this experiment, Fe and Zn were supplied by sources of iron (II) sulfate heptahydrate (FeSO4. 7H2O, 0. 5%) and Zinc sulfate heptahydrate (ZnSO4. 7H2O, 0. 5%), respectively. The traits examined in this study included germination percentage, radicle length, plumule length, seedling weight vigor index and the content of photosynthetic pigments and carotenoid. Results: The results of this experiment indicated that the plumule length was more sensitive to drought stress, as compared with the root length. With increased intensity of drought stress from 0 to – 0. 9 MPa, the content of photosynthetic pigments in Stevia significantly decreased in all the priming treatments, so that the lowest amounts of chlorophyll a, b and carotenoid were observed at the potential of – 0. 9 MPa. Priming with SA + Fe + Zn was found to be more effective than other treatments in improving the germination characteristics and the chlorophyll content of Stevia under normal and drought stress conditions. At the highest level of drought stress, germination percentage, radicle length, plumule length, seedling vigor index and total chlorophyll content increased by 55. 7, 50. 5, 74. 3, 90. 3 and 85. 5%, compared with the control in the concurrent application of Fe, Zn, and SA. Conclusion: In general, seed priming by micronutrient elements (Fe and Zn) and salicylic acid, and particularly their integrated application, could be recommended to increase the resistance of Stevia to drought stress in the germination phase.

Introduction: Pepper (Capsicum annum L. ), which belongs to the solanaceae family, is one of the most important vegetable and garden products. Due to its nutritional value, its use tends to rise all over the world. Germination and seed emergence are strongly influenced by environmental stresses such as salinity and drought. Drought stress affects various aspects of plant growth. It reduces germination, delays vegetative growth and reduces dry matter in the plant. Salinity stress, as an environmental stress, is a limiting factor for the growth and development of crops and garden production. Materials and Methods: The present study was conducted to evaluate the impact of drought and salinity stress on seed germination characteristics of sweet pepper (Capsicum annuum L. ) in two separate experiments, using a completely randomized design with three replications in the Faculty of Agriculture, University of Birjand in 2016. PEG 6000 was used for drought stress and NaCl, for salinity stress. The treatments included drought and salinity stress levels (0,-2,-4,-6,-8,-10 and-12 bars). Seeds were disinfected with sodium hypochlorite (2%) solution for 1 minute, and were then washed with distilled water. The medium was petri dishes with a diameter of 9 cm. 25 seeds were placed on two layers of filter papers in each dish. 5 ml of distilled water or solution was added to each petri dish. The measured traits were germination percentage, germination rate, seed vigor index, radicle length, plumule length, ratio of radicle length to plumule length and dry weight of radical and plumule. Results: The results indicated that salinity and drought stress had significant effects on seed germination characteristics of sweet pepper so that salinity stress with osmotic potential of-10 and-12 bar decreased the germination of sweet pepper and reached zero. Increasing salinity stress from zero to-12 bar decreased germination percentage, germination rate and seedling dry weight by 43. 75, 41. 67 and 93. 46%, respectively. The results indicated that with increases in both salinity and drought stress, seed vigor index decreased significantly. The results showed that with increasing drought and salinity stress from 0 to-12 bar, seed vigor index decreased 96. 58 and 100 percent, respectively. Conclusions: The results of this study showed that the tolerance of sweet pepper to salinity stress was higher than its tolerance to drought stress at the germination stage, but for more accurate evaluation, it is necessary to conduct additional experiments in the field and in the greenhouse.

Introduction: Due to their aggressive and competitive habits, weeds inhibit the growth of valuable plants. Interference in plants includes environmental competition and allelopathy (Autotoxicity and hetrotoxicity). In hetrotoxicity, chemical compounds released from plants are able to affect the neighboring plants. Proper management of weeds and the exploitation of their hetrotoxicity potential can reduce losses caused by weeds. This could also represent an effective step towards the reduction of the use of herbicides. Therefore, the purpose of this study was to evaluate the effect of hetrotoxicity potential of aqueous extract of various organs of Malva sylvestris L. weed on traits of germination and photosynthetic pigments of Echinochloa crus-galli L. Material and Methods: An experiment was conducted to evaluate the effect of hetrotoxicity potential of aqueous extract of Malva sylvestris L. weed including the stem, leaf and flower as well as their mixture on traits of germination and photosynthetic pigments of Echinochloa crus-galli L. as a completely randomized design in three replications in Weeds Science Laboratory of Gonbad Kavous University in 2017. For this experiment, aerial parts of M. sylvestris were first collected at the flowering stage from Ramian field. They were subsequently separated with great care and were powdered. Then from them, 5% suspensions (weight/volume) were prepared, using distilled water. Finally, the extract of each organ of M. sylvestris was added to Petri dishes containing E. crus-galli seeds. After the 7th day, traits such as rate and percentage of germination, radical and shoot elongation, vigor index, total content of chlorophyll a and b and carotenoids were measured. Results: The results showed that various organs of M. sylvestris and their mixture had different inhibitory effects on traits of germination and seedling length of E. crus-galli weed. The highest inhibition effects on rate and germination percentage and elongation of radical and shoot of E. crus-galli were obtained using leaf extract of M. sylvestris about 64. 04, 64. 37, 87. 69, 62. 81%. In this study, radical length is more affected under hetrotoxic compounds of various organs of M. sylvestris, as compared with shoot length. Based on the results, various organs of M. sylvestris and their mixture also have different inhibitory effects on chlorophyll and carotenoid content of E. crus-galli weed. It seems that the differential effects among different organs of M. sylvestris are a function of the threshold concentration of allelochemicals to hetrotoxic compounds of the organs, which causes various response by E. crus-galli. Conclusion: Given the evidence for the effect of hetrotoxicity potential of various organs of M. sylvestris on traits of germination and pigments of chlorophyll and carotenoid of E. crus-galli and huge biomass generated, it is advisable to exploit allelochemical compounds of this plant as bio-herbicides.

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 μ M) 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 μ M and 60 μ M could successfully enhance seed germination percentage, as compared with the aged seeds (i. e., control). A concentration of 45 μ M also improved the vigor of deteriorated seeds. Seed pretreatment of 15, 30 and 45 μ M 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 μ M cinnamic acid improved germination uniformity. The area under the curve was positively affected by 15μ M and 30μ M. Concentrations of 45 μ M and 60 μ M enhanced seedling dry weight. Applying 45 μ M 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 μ M 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.