Iranian Journal of Seed Research

Extended abstract
Introduction: Today, various technologies have been developed to improve seed quality with the aim of increasing the percentage, speed and uniformity of germination and improved seedling establishment under different environmental conditions. One of these technologies is seed pre-treatment or seed priming. In this regard, some studies confirmed that pre-treatment of seeds with hormones and plant growth regulators improve germination behavior and its related indices, including average germination time, seed vigor, radicle length, plumule length, germination rate and seedling establishment in primed seeds of sesame. Cognizant of the sensitivity of the germination process as the first plant developmental stage and the importance of improving germination indices and sesame seedling establishment, the aim of this study was to evaluate the seed priming efficiency, using salicylic acid, methyl jasmonate and humic acid in the germination performance, biochemical changes and early seedling growth of two sesame cultivars including Yellow white and local cultivar of Dezful.
Materials and Methods: This experiment was conducted as a factorial based on a completely randomized design with four replications in the seed technology Laboratory of Safi Abad Dezful Agricultural Research Center in the summer of 2015. The first factor was seed pre-treatment with distilled water (control), salicylic acid 0.1mM, methyl jasmonate 1µM, and humic acid 1.5% and the second factor was two varieties of sesame including Yellow white and the local cultivar of Dezful. Germination percentage, germination rate, seed vigor index, radicle length, plumule length, allometric coefficient, proline content, soluble proteins and catalase enzyme activity were determined to compare the treatments.
Results: The results of the experiment showed that seeds priming had a significant effect on germination percentage, germination rate, seed vigor index, radicle length, plumule length, allometric coefficient and seedling biochemical changes, and improved them. The effect of cultivar on all the traits studied, except mean daily germination and plumule length, was not significant. In this research, the Dezful cultivar had an average of 13.52 seeds per day with higher germination rates, compared with the other cultivar (Yellow white). In addition, the interaction of priming × cultivar was significant only in seed vigor index and allometric coefficient, where the comparison of the mean values indicated that the highest seed vigor was obtained by using humic acid 1.5% in the Dezful cultivar (10.09), while the highest allometric coefficient in seed pre-treatment with methyl jasmonate was found in the Yellow white cultivar (1.57).
Conclusions: In this study, the most effective seed priming treatments for improving germination, biochemical changes and seedling growth of sesame was humic acid 1.5%, recorded for the local cultivar of Dezful. Seed priming with humic acid 1.5% was significantly better than the control and Dezful cultivar’s germination performance was better than that of Yellow white cultivar; therefore it can be said that pre-treatment of seed with humic acid with significant effects on germination characteristics of sesame can be more effective in establishment of seedlings. It is advisable to use this organic acid for better root system development and sesame seedlings establishment, which is a major problem at the beginning of the growing season.
 
Highlights:

1. Humic acid was the most effective seed priming treatment on germination characteristics, biochemical changes and seedlings growth of sesame.
2. The effect of seed priming treatments on the germination characteristics of the Dezful cultivar was more pronounced than that of Yellow white.

Introduction: In addition to dormancy, seeds of Allium hirtifolium have a weak emergence in the field. Among methods for improving the efficiency and emergence of seeds, nutritional priming can be considered for its performance on weak seeds. The presence of micronutrients is one of the factors that may affect the efficiency of the seeds. Therefore, the aim of this study was to investigate the effect of priming with nutrients on optimization of dormancy status, germination, and enhancement of shallot seeds for its conservational, restoration and domestication programs.

Materials and Methods: In order to study effects of nutrients on germination and emergence of Allium hirtifolium, a CRD factorial experiment was conducted with four replications at Seed Science and Technology Lab of Shahrekord University in 2015. Two dormancy breaking treatments (sulfuric acid and sulfuric acid + gibberellic acid) as the first factor and nine nutrition treatments including four levels of ZnSO₄ (5, 10, 50 and 100 mM) and four levels of FeSO₄ (0.5, 1, 1.5 and 2%) versus control were compared on shallot seeds.

Results: The results showed that dormancy breaking treatments, nutrient pretreatment of seeds and their interaction had significant effects on germination percentage, germination rate, time to reach l0% and 50% germination, germination uniformity, seedling length and vigor index I at 1% probability level. Sulfuric acid and FeSO₄1% increased germination versus control. Application of gibberellic acid affected the behavior of iron but did not indicate significant effects for zinc. The concentration of 5 mM ZnSO₄ increased the rate of germination, compared with the control but decreased with higher concentrations. The gibberellic acid did not show any sharp effects on germination rate. Time to reach 50% germination was also affected by FeSO₄ 0.5% and 1% and lower levels of zinc. Application of gibberellic acid did not show any significant impact on the germination time reduction, compared with control and increased T₅₀ in higher concentrations. Although germination traits were rarely affected by gibberellic acid, seedling length and vigor index were positively influenced with GA, and the highest seedling length was achieved at 0.5 and 1% of iron and gibberellic acid.

Conclusion: Seed priming with nutrients can improve germination and plant vigur indices. Different concentrations of iron and zinc showed different impacts on the seeds, which showed interaction with dormancy breaking methods. Although application of gibberellic acid did not have an effective role in increasing germination rate and reducing the time to reach 10% and 50% of germination, it enhanced seedling length and vigor index I, especially for iron.

Extended Abstract
Introduction: White Astragalus (Astragalus gossypinus Fisherr.) is one of the valuable plants for producing gum, which is of critical importance in soil conservation and the economy of the country. This plant is propagated by seed; its seeds are in the natural state of dormancy. Therefore, recognizing the factors affecting dormancy and creating optimal conditions for seed germination of this plant is necessary for the cultivation and reclamation of rangelands. This study was conducted with the aim of finding the best treatment for breaking the dormancy and improving seed germination under various chemical and physical treatments.
Materials and Methods: The experiment was carried out as a factorial based on a completely randomized design with four replications at the gene bank of cereal and legume Lab of Ilam University, 2017. The factors included two levels of scarification chemical (with and without sulfuric acid (H₂SO₄) for 10 minutes), three levels of stratification (control, moist chilling at +4 °C and dry chilling -20 °C), potassium nitrate in two levels (zero and 1% KNO₃) and gibberellic acid in two levels (zero and 5 ppm GA₃). Germination indices including germination percentage, germination rate, seedling and radicle length, seedling fresh weight and vigor index were measured.
Results: Initial assessment of vital indices in seed such as germination and primary growth showed that the simultaneous application of scarification by sulfuric acid and moist chilling at +4 °C has the most impact on removing dormancy and increasing germination percentage. The highest germination rate was observed in moist chilling at +4 °C, which was 32.19 percent more than that of the control treatment. Scarification by sulfuric acid reduced the mean germination time in moist chilling at +4 °C. Scarification by sulfuric acid increased the fresh weight of the seedling by 55.25 percent, compared with the control. Pre-treatments with potassium nitrate undre control conditions, moist chilling at +4 °C and dry chilling at -20 °C increased the fresh weight of seedlings, at 52.66, 30.94 and 17.18 percent, respectively. Application of potassium nitrate increased root length by about 60.7 percent, compared with control. The highest radicle length (78.71 mm) was obtained when the seed was treated with sulphuric acid with wet chilling at 4 ° C for two weeks, which was 30 percent higher than control. The highest seedling length (84.88 mm) was obtained in scarification with sulfuric acid, wet chilling, and potassium nitrate and gibberellic acid. The highest seed vigor index (61.85 %) was observed in the treatment of scarification with sulfuric acid under moist chilling, and pre-treatments of gibberellic acid and potassium nitrate.
Conclusions: In general, it can be concluded that seed dormancy of Astraglus gossypinus involves both physical and physiological dormancy. The best treatment for removing the dormancy of this species seems to be scarification with sulfuric acid for 10 minutes puls concentrated stratification in moist chilling at +4 °C for two weeks.
 
 
Highlights:

1. Determination of the optimal seed dormancy techniques of white Astragalus for the purpose of increasing seed germination percentage.
2. Comparison of the efficiency of different dormancy breaking techniques.
3. The combined effect of sulfuric acid, chilling and priming with gibberellic acid and potassium nitrate on germination indices.

Introduction: Agriculture has been influenced by different abiotic stresses such as temperature, drought and salinity, which reduces roughly half of the yield of crops. In many forage plants, germination and early seedling growth are the most sensitive stages of their growth in the face of environmental stresses. Current research was conducted to study the effects of drought and salinity iso-osmosis stresses on germination indices and growth parameters of three clover species, including Trifolium resupinatum, T. alexandrinum and T. incarnatum.

Material and Methods: Two separate experiments (drought and salinity) were conducted as a factorial experiment based on a completely randomized design with three replications. The test factors included clover species with three levels, including T. resupinatum, T. alexandrinum and T. incarnatum and different levels of drought and salinity potentials (0, -2, -4, -6, -8, -10 and -12 bar) due to polyethylene glycol 6000 (PEG 6000) and sodium chloride (NaCl), respectively. Sterile disposable petri dishes with a diameter of 10 cm were used, in each of which, 27 seeds were placed on filter paper and then 5 ml of the desired treatment solution was added to each. Petri dishes were then placed in a germinator at 20°C and relative humidity of 75%. After the end of the desired time germination (About 14 days), from each petri, germination percentage and rate, number of secondary roots, time to get 50% germination (D50), root to shoot ratio and the number of abnormal seedlings were recorded.

Results: Inhibitory effects of salinity and drought stresses affected all germination indices. Germination percentage, rate of germination, root and shoot length all decreased with increasing stress levels, while time to get 50% germination (D50) increased with the increase in stress levels. Under both drought and salinity, all growth parameters of Trifolium resupinatum were higher than the other two species. Germination percentage of T. incarnatum was 0% at -12 bar of drought, but germination of T. resupinatum and T. alexandrinum was 70.33% and 7.33% at -12 bar of these stresses, respectively. Under salinity conditions, all the seeds of the three species germinated at -12 bar. Root to shoot ratio increased with increasing stress levels and at high stress levels, it decreased. The decreases were 41.39% and 0% in drought and salinity, respectively. The number of secondary roots increased with increasing stress levels and the maximum number was observed in Trifolium alexandrinum which was 5.42 and 1 in drought and salinity, respectively. The number of abnormal seedling increased with increasing salinity levels, while under drought conditions there was no abnormal seedling.

Conclusion: Comparison of the effects of sodium chloride and polyethylene glycol showed that sodium chloride reduced germination index due to toxic effects or osmotic effects more than polyethylene glycol solution. ­­­­­­­­­­­­­­­­­­­It seems that Trifolium resupinatum has the best yield in both drought and salinity stresses, and that in drought condition, Trifolium alexandrinum, and in salinity stress, Trifolium incarnatum have the best performance.

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: In Iran, the majority of research has been done on the depth of burial on crops and the effect of these factors on weeds resulted from seeds and rhziomes of seedlings has been less studied. Strangle Wort weed is one of the most problematic weeds in sugarcane fields, orchards, especially pistachio orchards, barren lands, and roads. Thus, this study aimed to find out the effect of different levels of burial depth and flood stress on the extent and quality of seedlings resulted from its rhizomes.
Material and Methods: Two separate greenhouse experiments based on completely randomized design with four replications were conducted in the experimental farm of Sugarcane Research Institute of Khuzestan province at 2014-2015 growing season. Flooding stress treatment included 7 levels of flooding stress (4, 8, 16, 24, 48, 72, and 96 flooding hours) and 6 levels of seed burial (1, 3, 5, 7, 10, and 15 cm) and rhizome burial depth treatment included 7 levels (1, 3, 5, 7, 10, and cm 15).
Results: With increasing levels of flood stress, all studied traits including root length, stem height, total dry matter biomass, shoot dry weight and root dry weight of strangle wort rhizomes decreased at 96 hours of waterlogged stress compared to the control by 63, 70, 59, 98 and 74 percent, respectively. Also, in second experiment, buried rhizomes of this weed with a length of 5 cm at a depth of 15 cm were not able to produce new seedlings.
Conclusion: According to these results, for proper management of this weed, highly contaminated areas in the field should be identified (especially in sugarcane fallow fields because at this time there is no weed control limitation). Then, the weed should be turned it into pieces smaller than 5 cm with plowing tools. Also, if possible, with suitable tools, transfer rhizomes should be transferred to a depth of more than 15 cm and integrated weed control management with drought and flooding stress and burial depth with at least two times of plowing could be implemented to control weed and prevent its expansion.

Highlights:
1-Germination characteristics of strangle wort seedlings under burial depths and flooding stress were evaluated.
2-The effect of burial depth and flooding stress on control and management of strangle wort was examined.
3-Precise determination of weed biology and weed germination behavior will lead to proper execution of weed control program.

Extended abstract
Introduction: Small size of Satureja (Satureja hortensis L.) seed causes many problems in mechanized cultivation and its seed consumption is increased significantly.  The approach discussed in the present study is the seed coating of Satureja by several matters and selecting the suitable method as well as investigation of adding hormonal and nutritional substances to the selected coating material for better emergence and the elimination of problem arise as a result of coating.
Materials and Methods: Purified Satureja seeds (97%) were prepared and poured into the coating machine at a specified amount. First, 1% solution of benomyl fungicide was sprayed on the seeds. Then some coating powder was sprayed on the spinning wet seeds inside the machine. Then some of the adhesive solution was sprayed on it and again the coating powder was added and this was repeated several times to create a suitable form for the coated seeds. This was repeated using different materials and among these coatings powder, vermiculite and perlite provided better coating on Satureja seed. Then, different materials including gibberellin, BAP, cytokinin, thiourea (CH₄N₂S) and potassium nitrate (KNO₃), phosphorus from H₂PO₄ source and manganese sulfate (MnSO₄) were used to the emergence of the enlarged seeds and also, the emergence of these seeds were evaluated in the greenhouse.
Results: Initial results showed that vermiculite and perlite provided better cover for Satureja compared with the other coating materials. Investigating the emergence of perlite-coated seeds in the greenhouse showed that gibberellin (all concentrations) and kinetin (500 mg/l) present in the seed coat improved the Satureja seed emergence under greenhouse condition. Also, it was found that Thiourea (700 and 7000 mg/l), potassium nitrate (7, 70, 700 mg/l), phosphorous (9 kg/100 kg seed) and manganese sulphate (2 and 4 mg/l) present in the coat significantly increased the Satureja seed emergence and led to improved seedling growth.
Conclusion: Perlite for the purpose of seed pelleting of Satureja showed good results and the use of gibberellin (at all concentrations) and quintine (500 mg/l) in the seed pelleting improved germination of pelleted Satureja seed.
 

Highlights:
1- Technical knowledge of Satureja seed pelleting was obtained.
2- The suitable material to improve the emergence of pelleted Satureja seed was introduced.

Extended Abstract
Introduction: Seeds need successful germination at the optimal time and conditions to survive. Sometimes, even in the best environmental and genetic conditions of the seed, they do not germinate or germinate with a delay, which are called dormant seeds. Seed dormancy can have positive effects on avoiding adverse conditions and ensuring survival in the environment. However, dormancy in crop plants reduces emergence and yield by preventing germination. A combination of environmental and seed genetic factors are involved in seed dormancy formation. In general, seed dormancy includes: physical dormancy, physiological dormancy, morphological dormancy, morphophysiological dormancy and combinational dormancy, and physical / chemical scarification treatments, hot and cold stratification, leaching, hormonal treatments, after-ripening, light and combination treatments can be used to eliminate dormancy depending on its type. Therefore, in this study, using domestic studies conducted in the field of seed dormancy in different plant species, identification of dormancy in different plant species and its types have been discussed, and general and practical information in this regard has been provided.
Materials and Methods: In this study, 168 reports published on 250 plant species in the last 20 years, which were published in the seed dormancy of medicinal plants, weeds, rangelands, ornamentals and crops were investigated. Then, the percentage of plants studied and their families, as well as the share of different types of seed dormancy and appropriate treatments to for its eliminate were determined.
Results: Among the plant species studied, the most freuqent type of dormancy was related to physiological dormancy (50%), followed by physical dormancy, combinational dormancy, morphophysiological dormancy and the lowest share of dormancy in the studied plant species was related to morphological dormancy (1.61%). The most effective treatments to eliminate physiological dormancy were the use of cold stratification, gibberellic acid, and potassium nitrate. Also, the most effective treatments for the removal of physical dormancy were the use of physical / mechanical scarification treatments, chemical scarification and potassium nitrate treatment. According to the results, temperature treatments and then gibberellic acid and potassium nitrate treatments are recommendedt eliminate morphological dormancy. To eliminate morphophysiological dormancy, it is recommended to use treatments to maturate differentiated small or undifferentiated seeds (removal of morphological dormancy) as well as treatments to counteract the germination inhibitory factors or to compensate the were applied the most to eliminate morphophysiological dormancy.
Conclusion: By identifying the type of dormancy and applying the appropriate treatments, the germination of economical and valuable plants can be improved.

Highlights:
1- Dormancy types in native plant species of Iran through the information of domestic studies was investigated and a comprehensive report on seed dormancy was presented for the first time.
2- General and practical information about seed dormancy, effective factors and methods of dormancy elimination was reviewed in a practical way.

Extended Abstract
Introduction: Structural and physiological delicacy of soybean seeds is known as an important quality indicator in the cultivation of this plant, but at the same time, the most chronic problems of soybean seed quality are the reduction of seed quality during storage and before sowing. The effect of some nutrients on the quality of soybean seeds under accelerated aging stress was investigated
Materials and Methods: Experiments were conducted for two consecutive years (2019-2020) in the research field of Lorestan University, Faculty of Agriculture in a randomized complete block design. Nutritional treatments included nitrogen and phosphorus application (as soil application) and iron and molybdenum as foliar application. Seeds were harvested at the maturity stage and 1000-grain weight and seed coat resistance to mechanical damage was investigated. Following the exposure of seeds to accelerated aging, leakage from seeds and germination were measured.
Results: The results showed that nutrition had a significant effect on all studied traits. However, the effect of year was only significant on 1000-seed weight and resistance to mechanical damage of seed coat. The highest number of traits related to seed quality was related to complete fertilizer treatment (N-P-Fe-Mo) and accelerated aging had a less negative effect on them.
Conclusion: Among the nutrients, nitrogen and phosphorus had the most effect on germination indices, and iron and molybdenum were in the next ranks. Seeds with strong vigor and treated with fertilizer were less affected by accelerated aging and had better germination. The lower the seed vigor, the more sensitive they were to this stress.

Highlights 

Extended Abstract:
 Introduction: Production of high-quality seeds to stabilize crop yield is an important challenge for breeders. One of the most important answers to this challenge is to clarify the molecular mechanisms associated with seed vigor characteristics. Functional proteins of Cupin superfamily are among the molecules in signaling pathway. Previous research has shown that in maize, a storage protein similar to the functional Cupin superfamily protein called ZmGLP is effective in seed germination. However, in the previous experiments, suitable indicators were not used to assess seed vigor and its relationship with field establishment. So, it is needed to study the performance of ZmGLP in predicting field emergence to complete the previous research.
 Materials and Methods: An experiment was performed on 14 samples of commercial inbred maize lines. In this experiment, in addition to the laboratory evaluation of seed germination, field indices of physiological seed quality including the percentage of seedling emergence in the field, time to 50% seedling emergence, time to 90% seedling emergence, seedling dry weight, seedling height and coefficient of variation of seedling height was also assessed. In the polymerase chain reaction, two pairs of primers (CF / CR primers and IDF / IDR primers) were used to identify the DNA sequence of the Cupin.
Results: The results show that the seeds were different in terms of physiological quality. The lowest percentage of germination in laboratory was related to K1264/1, while the lowest physiological quality of seeds in field indices was observed in K1263/17. The molecular test confirmed the presence of the desired allele at the InDel9 site of vigor-related genes in the three samples of B73, K1264/1, and K1264/5-1, but no amplification band of the InDel9 site was observed in all K1263/17 seed samples. Due to the fact that line K1264/1, which had the lowest germination percentage in the laboratory, had an amplification band at this related site to vigor, it is not enough to rely on the results of the laboratory germination test to investigate the relationship between this gene and seed vigor. The field emergence test and seed vigor test that have a good prediction of field emergence must be used in these studies.
Conclusions: According to the results of this experiment, molecular tests with functional markers based on Indel9 can be used to accelerate the evaluation of vigor, especially when the breeder is breeding a new line or hybrid. It is a useful, rapid, and effective molecular method to predict seed emergence in the field and screen the lines to ensure the genetic strength of the germination of the lines, especially in the temperate germplasms of corn. Finally, it is necessary to determine the threshold of low vigor during seed quality investigation in different cultivars, and relationship between the presence or absence InDel9 site should be considered in future research.

Highlights:
1- The feasibility of using molecular markers to determine the seed vigor of corn lines in the field was studied and optimized for the first time.
2- The results of physiological quality assessment of seeds in the field for the studies related to the relationship between molecular markers and seed vigor were exploited for the first time.
3- The Indel9 site and molecular markers related to seed vigor in the field were introduced.