Iranian Journal of Seed Research

In order to study the effect of alkaline stress on seed germination and seedling biochemical characteristics of two safflower cultivars, a laboratory experiment was conducted based on a completely randomized design with three replications in the Vali-e-Asr University of Rafsanjan. Experimental factors included the levels of alkaline with sodium bicarbonate (0, 10, 20, 30, 40, 50 and 60 mM) and two cultivars of safflower (Soffeh and 411). The result showed that alkaline stress had significant effects on seed germination characteristics. Increasing alkaline stress reduced percentage and rate of germination, length and dry weights of shoots and roots, K+ concentration and K+/Na+. However, alkaline increased malondialdehyde content, proline, total carbohydrate and Na+ concentration. In alkaline stress condition, there was a significant difference between cultivars in length of shoots and roots, proline content and K+ concentration. 411 cultivar showed notable superiority compared to Soffeh cultivar. Both cultivars had the highest malondialdehyde at 60 mM alkalinity and the lowest malondialdehyde obtained in Soffeh cultivar and control. The result of this research showed that 411 cultivar was better than Soffeh cultivar in proline and soluble sugar content, but these two cultivars had no significant differences in other traits.

Rapid germination is an important factor determining the final yield. This study was performed to investigate the effects of different levels of methanol and drought stress on germination characteristics of lentil seedlings. The experiment was conducted in completely randomized design with three replications in summer 2014 at the Khatam Alanbia University of Behbahan. The first factor was different levels of methanol equal to 0 (control), 5, 10 and 15 volumetric percentage (v/v), and the second factor we negative water potential in four levels 0, -3, -6 and -9 bar by PEG. Results showed that there was a significant difference between different methanol concentrations regarding germination percentage, germination speed index, plumule and radical length, plumule and radical dry weight, radical area, radical diameter and consumed endosperm (P 0.01). Different levels of methanol caused a significant decrease in germination characteristics compared with to control. Drought stress with -9 bar level significantly decreased germination percentage, germination speed index, plumule and radical length, plumule and radical dry weight, radical area, radical diameter and consumed endosperm compared to other levels. Effects of drought and methanol were significant differences regarding the germination speed index, plumule length, plumule dry weight and consumed endosperm (P 0.05).

In order to evaluate the effect of priming on some germination and seedling growth characteristics of safflower (Carthamus tinctorius L.) under drought stress, an experiment was conducted base on completely randomized design with four replications at the Seed Technology Laboratory of Yasouj University, in 2011. Treatments were included of five priming levels (control or no prime, hydro priming, potassium nitrate 3% (KNO3), PEG and Urea -4 bar) as the first factor and three levels of drought stress (0, -4 and -8 bar) as the second factor. The results showed that the interactions of drought stress and seed priming on germination percentage and the germination rate was not significant. But the main impact of priming and drought stress on them was so significant at 1% probability. The highest germination percentage and germination rate (75.66% and 3.62 seed.day-1, respectively) were shown in urea priming and the lowest (52% and 2.31 seed.day-1 respectively) in the control treatment (no prime). Drought stress was caused a significant decrease in germination traits. In general, the results obtained in this study showed that treatment with urea and potassium nitrate compared with PEG improved germination and seedling growth of safflower.

To evaluate the interaction of Cd and SA on seed germination of Safflower (Carthamus tinctorius L. cv. Soffe), this experiment was carried out as a factorial based on CRD with four replications in 2012, in Yasouj University seed lab. Factors included of four levels of seed priming with SA (0, 0.3, 0.6, and 0.9 mM) and eight levels of cadmium nitrate (0, 5, 10, 15, 20, 25, 30 and 35 mM). In all Cd treatments, SA 0.9 mM had maximum germination percentage (84% in 0 mM Cd) and rate (6.58 seed day^-1 in 5 mM Cd), radical length (4.21 cm in 0 mM Cd) and stem (3.29 cm in 0 mM Cd), radical dry mater (2.25 mg in 0 mM Cd), shoot dry matter (0.94 mg in 0 mM Cd) and seed vigor index (6.30 in 0 mM Cd). Generally, seed priming with SA decreased the impact of Cd on seed germination and SA 0.9 mM was the best treatment.

In order to study of drought stress and normal irrigation effect on seed germination and seedling vigor of 10 oilseed rape spring genotypes, RGS003, Sarigol, Option 500, RGS006, 19_H, ORS3150-3006, ORS3150-3008, RG4403, RG405/03 and RGAS0324, an experiment was conducted as factorial, based on a completely randomized design with four replications, in the seed analysis laboratory of Seed and Plant Certification and Registration Institution at Karaj during 2013. Results indicated that RG4403 genotype by 3.498 gr. and RGS006 genotype by 3.082 gr had the highest and lowest one thousand seeds weight respectively. Seeds of Sarigol, Option500 and RGS006 genotype, respectively, by normal irrigation and drought stress, had the most primary root, shoot and seedling length and seeds of ORS3150-3008 and RGAS0324 genotypes by normal irrigation respectively had the most primary root and seedling and primary shoot and seedling dry weight. Seeds of Sarigol and RGAS0324 genotypes by normal irrigation had the highest final germination percent. The highest mean germination time, the coefficient of the velocity of germination and mean daily germination, also respectively belonged to seeds of RGS003genotype by drought stress and19-H and RGAS0324 genotypes by normal irrigation. Besides, Sarigol and RGAS0324 had the most length and weight vigor indices. Generally, results showed that drought stress at flowering and maturity duration caused a decrease in seed quality of studied genotypes, but under what conditions, some genotypes like RGS006, 19-H and ORS3150-3006 seed had relatively optimum germination quality and seedling vigor traits.

This study was performed to investigate interactions of different levels of vermicompost extract and salinity stress on germination characteristics of chickpea seedlings. The factorial experiment was conducted in completely randomized design with three replications. Concentrations of vermicompost extract (0, 5, 10 and 20 volumetric percentage) and salinity levels (0, 30, 60 and 90 mM NaCl). Results showed that there were significant differences (P‌ 0.01) between vermicompost extract and salinity levels regarding germination percentage, radicle length, and shoot dry weight. Salinity stress with 90 (Mm NaCl) level significantly decreased all of the traits compared to the non-stress condition. Effects of vermicompost extract and salinity stress were significant differences (P‌ 0.05) on the germination rate index, radicle length, radicle dry weight and consumed endosperm. vermicompost extract at concentrations of 5 volumetric percentage in moderate salinity stress (30 mM NaCl) and non-salinity stress caused a significant increase (P‌ 0.01) in radicle length, radicle dry weigh and consumed endosperm compared to control.

In order to determinate the cardinal temperatures and investigate the effect of temperature on seed germination and seedling growth of Securigera securidaca, a study was conducted in a completely randomized design with 8 temperature treatments (5, 10, 15, 20, 25, 30, 35 and 40^oC) and four replications in research laboratory of faculty of agriculture at the Birjand University in 2013. A two-segmented linear regression model was fitted between germination rate and temperatures to determine cardinal temperatures for germination. Cardinal (minimum, optimum and maximum) temperatures of germination were determined as -1, 22.5 and 40.2^oC respectively. Maximum rate and percentage of germination obtained in the range of 20-25^oC. Maximum of radicle length and dry weight, maximum of caulicle length and dry weight and maximum of vigor seedling were obtained in 20^oC,10-20^oC and 5-30^oC respectively. Maximum and minimum germination uniformity (GU) was obtained in 25 and 5^oC. 

Allelopathic compounds display an important role in biodiversity, stability and ability of ecosystem production. An experiment was conducted to investigate the allelopathic effect of six species, Cordia myxa, Melia indica, Delonix regai, Terminalia catappa, Eucalyptus camadulensis, Ficus religiosa on germination and seedling growth of Calendula officinalis. An experiment was performed in a completely randomized design with three replications in the lab of the horticultural Hormozgan university during 2014. A completely randomized design with three replications was carried out in the laboratory. Results indicated that the percentage of germination, seed germination rate, plumule and radicle length, and seed vigor of Calendula officinalis significantly reduced under aqueous extract of all species. But, there was no significant difference between dry weights. Delonix regia extract ceased the seed germinates in both concentrations. After that Melia indica extract had a highly significant inhibitory effect on seed germination, plumule and radicle length when compared to control. The results of this experiment also showed that the inhibitory effects of Cordia myxa and Terminalia catappa were lower in compared to other species. Between two concentrations, 100% concentration has a more inhibitory effect. The results of the present study revealed that inhibition of germination and growth parameters of Calendula officinalis showed variation according to the different plants. Cultivation of Calendula officinalis with Melia indica, Delonix regia species don’t suggest in the landscape.

In order to evaluate the effect of hydropriming on seed germination of Vigna radiata under salinity stress, an experiment was arranged in a factorial based on a completely randomized design with three replications in the laboratory of the Agricultural College of the University of Ramin Khuzestan. Treatments were salinity stress at 4 levels (0, 3, 6 and 9 Mmhos) and hydro priming at 3 levels (1, 1.5 and 3 h) and two sizes of seed (small and large seeds) that was carried out by NaCl. Results showed that all of the germination characteristics decreased with increased salinity, but this decrement for seeds that primed at a long time, was less. Also at all characteristics, small seeds, showed better reactions than large seeds. Generally, hydropriming was improved germination characteristics of Vigna radiata under saline conditions. According to this experiment, hydropriming improved germination and establishment.

In order to evaluate the effect of seed moisture content at harvesting time and drying temperature on soybean seed germination characteristics, an experiment was conducted as factorial (2×3×2) based on Randomized Complete Block Design with three replications in Karaj and Moghan areas. The first factor was cultivar with two levels (Williams and L₁₇), the second factor was seed moisture content with three levels (15, 20 and 25%) and the third factor was drying temperature with two levels (30 and 45 °C). Results show that the germination percentage of producing seeds in Karaj (81.3%) were higher than Moghan area (77.4%). The difference between the germination percentage of dried seeds at 30 and 45^◦C with initial seed moisture content of 15% was about 5.5%, while this difference for seeds with 25% initial moisture content was about 18.5%. There was no significant difference between seedling vigor index of seeds with 15% moisture content of two cultivars that have been produced in Karaj, but at 20% moisture content, the seedling vigor index in Williams cultivar (139.7) was higher than L₁₇ cultivar (107.3). The highest (51.42 µsm cm^-1 g^-1) electrical conductivity of seed leakage soluble was obtained from the L₁₇ cultivar with 25% moisture content and 45^◦C and the lowest (28.46 42 µsm cm^-1 g^-1) rate of it was observed in Williams cultivar with 20% moisture content and 30^◦C. According to these results, we must harvest and dry soybean seeds at 30^◦C when its moisture content reached under 20%.

Select the appropriate tree species and compatible with harsh environmental conditions, with a high survival rate and optimal growth, is very important in the principled forestation projects. Offering moisture - temperature - time seed germination model is one of the solutions to the prediction of seed germination patterns as in this study, germination behavior model in four replications of 50 seeds of Cupressus arizonica (dishes 11cm) on the incubator was examined by applying five levels of water stress (0, -0.5, -1, -1.5, -2 MPa) and temperature treatments (10, 15, 20, 25, 30 °C). The results showed that the optimum temperature (To) and the basic temperature (Tb) for germination is 19.23±0.5 and 6.54 ± 0.0 °C respectively, and amount of the hydro time constant (θ_H) for this species is 0.29±0.11. According to the results, temperature and water potential factors and their interaction affected significantly on time and percent germination. Value of the hydrothermal time model was determined by using θ_HT= [(Ψ-Ψ_{b (g)}) (T-T_b)] tough model that its rate was 126.3 MPa°C. d with 0.87 coefficients of determination.

In recent years the use of allopathic effects on weed management seems to have attracted many professionals. In order to investigate the effect of aqueous extracts of Yarrow (Achilla wilhelmsii L.) and Habek mint (Mentha longifolia (L.) Huds) medicinal plant on germination indices of plantain, two experiments were conducted in completely randomized design with three replications in 2014 in the laboratory of seed technology of Yasouj university. Treatments consisted of 0, 25, 50, 75 and 100% concentrations of aqueous extract of Yarrow and Habek mint aerial parts. The results showed that the extract of Yarrow and Habek mint aerial parts on germination percentage, root and shoot length, root and shoot fresh and dry weight and seed vigor was significant. The maximum percentage and rate of germination have belonged to the control treatment (distilled water) and by decreasing the aqueous extract concentrations of each plant, the percentage and rate of germination increased. The minimum percentage and rate of germination have belonged to 100% concentration of aqueous extract that had no significant difference by 75% concentration. Finally, these results showed allelopathic effects of aqueous extract aerial parts of Yarrow and Habek mint, as a bio-herbicide on growth and germination of plantain.

Marigold (Calendula officinalis) is a medicinal plant belonging to the Asteraceae family, which seems necessary the review of its various features especially the improvement of reproduction in order to the development of vegetation and extraction of raw pharmaceutics materials. In order to study the effects of seed hardening on the quality of seeds harvested from different positions of inflorescence on the storability of pot marigold, an experiment conducted at the University of Mohaghegh Ardabili in 2011. Seeds hardened before planting with CaCl₂ 2% and distilled water. At harvest, the seeds collected from both inner and outer regions of the inflorescence from storage experiments in the laboratory. Harvested seeds stored for six months at 40°C. Then an experiment conducted as factorial based on a completely randomizes design with four replications at the laboratory. Results showed that the highest germination percentage (96%), rate (3.91 day^-1), radicle length (5.71 cm) and seed residual dry weight (0.061 g) were related to outer positioned seeds. The highest plumule length (4.79 cm) and seedling dry weight (0.016 g) obtained from outer seeds hardened with distilled water. In conclusion, for best stability results of pot marigold seeds, it is recommended to harden seeds before planting with water and harvest outer seeds from the inflorescence.

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In this study, the effect of different doses of gamma radiation was investigated on seed germination factors of Caper species. Gamma irradiation was performed using a cobalt-60 radiation with the radiation speed of 0.018 Gray/second and five doses of gamma radiation (0, 20, 40, 60 and 100 Gray) in a completely randomized design with 4 replication. The results showed that gamma radiation significantly affects some of the seed germination factors. So that the 100 Gray treatment increased the germination percentage up to 43.2% as compared with other treatments. The average time of germination in seeds treated with gamma decreased 0.91 days rather than control. Length of the stem let in gamma treatments increased 62.3% rather than control; so that the fresh and dry weight of stem let at 100 Gray were respectively increased 171.4 and 27.3% in comparison with the control. The fresh and dry weight of rootlets were respectively increased 417.9% and 668% rather than the control one. Seed vigor at 100 Gray was 32.3% higher than the control. From among the different studied doses, 100 Gray showed the highest influence on the seed germination and physiology although the induced changes were in low amounts. This study revealed that gamma irradiation has not major influences on improving seed germination characteristics of Caper shrubs.

Medicinal barberry plants, belong to Berberidaceae family. Seeds of barberry have long period dormancy. Therefore, overcome to seed dormancy and increasing germination rate of seeds due to different methods will be useful. In this regard, two separate experiments were designed. In the first experiment, effect of different levels of Gibberellic acid (0, 600 and 900 mg.l^-1 at 8˚C) and temperatures (25 (control), 10 and 5 °C at 50 days) in a factorial experiment based on the completely randomized design with three replications and in the second experiment, effect of different nutrition concentrations of MS medium (full strength MS, 1/2MS and 1/4 MS) in a completely randomized design with three replications on embryo culture of four native species of barberry (Berberis integrima, B. vulgaris, B. crataegina and B. orthootrys) were investigated. Based on the results obtained from the first experiment, chilling treated seeds showed the greatest effect (88%) on seed germination in comparison with gibberellic acid treatment. The results of the second experiment showed that the best MS concentration for embryo culture was full strength MS medium with%100 seed germination in four above mentioned barberry species after 2-3 days. In general, the best method to overcome barberry seed dormancy was an embryo culture in full-strength MS nutrition.

The seed pretreatment with salicylic acid has an important role in improving seed germination and increasing plant resistance to environmental stresses. This study was performed to investigate the effect of salicylic acid on seed germination of Milk thistle under salinity and drought stress. A factorial experiment was conducted in a completely randomized design with three replications. Treatments consisted of 4 levels of salicylic acid (0, 100, 200 and 300 mg/l) and four levels of each drought and salinity stress (0, - 4, - 6, - 8 Bar). The results showed an interaction effect between pretreatment with salicylic acid and drought and salinity stresses was significant at the 1 % level. On high salinity level (-8 Bar), seed germination percentage and rate, root and shoot length, fresh and seedling dry weight reduced significantly. The short length, fresh weight and percent germination reduced in all three levels of drought stress. Pretreatment with salicylic acid (200 and 300 mg/L) significantly reduce the harmful effects of drought and salinity stress (-6 and -8 Bar) on germination and seedling growth parameters of Milk thistle. The results of this experiment showed that seed treatment with salicylic acid can lead to increase the resistance of Milk thistle to salinity and drought stress in seed germination.

Germination is the first and the most stages for sainfoin (Onobrychis viciifolia) growth; which it has especially sensitivity to environmental stresses such as alkalinity. The current study was conducted to evaluate the effectiveness of seed pre-treatment methods on improving sainfoin tolerance to alkali stress in germination, early growth and its recovery as a factorial experiment based on a completely randomized design in College of Agriculture, Shiraz University in 2013. The first factor was four seed pre-treatment methods (seed with the pod, seed without the pod, pre-chilling of seed without pod and hydro-priming of seed without pod) and the second factor was five alkali stress levels (pH= 6.7, 7.9, 8.9, 9.8 and 10.7). Alkali stress levels were prepared using two neutral salts (Na₂SO₄ and NaCl) and two alkaline salts (NaHCO₃ and Na₂CO₃). The results showed that germination percentage was decreased as alkalinity (pH) levels were enhanced; so that, there were no germinated seeds in 9.8 and 10.7 treatments. Alkali stress reduced initial germination percentage (51.9%), final germination percentage (51.8%), plumule length (55.7%) and radicle length (72.2%). Under all alkalinity conditions, the lowest seed germination and seedling growth were observed in with pod seed, followed by pre-chilling treatments; while their highest were achieved in without pod seeds and hydro-priming treatments. The highest recovery was observed in without the pod, followed by hydro-primed seeds. Recovery was observed in Pre-chilled and with pod speeds up to 7.9 and in hydro-primed and without pod speeds up to 8.9.

The objective of this research was to evaluate the effect of salicylic acid and gibberellic acid on germination characteristics and changes of proline, protein and catalase activity of Brassica napus seedlings under Cu(SO₄) stress. The experimental design was factorial with complete randomized design as a base design with 3 replications. The first factor was 4 levels of Cu(SO₄) stress (0, 10, 20 and 30 mg/l), and the second factor was 4 levels of priming with salicylic acid and gibberellic acid 50 mg/l, hydro prime and control (non-priming). Results showed that with increasing levels of Cu(SO₄) stress, germination characteristics (germination percentage, germination rate, normal seedling percentage, seedling length and seed vigor index) reduced and using of salicylic acid, gibberellic acid and hydro prime increased germination characteristics. The highest germination percentage (94%), germination rate (30.75 seed per day), normal seedling percentage (86.17%) seedling length (10.53 cm) and seed vigor index (9.08) were attained from priming by salicylic acid 50 ppm under non-stress conditions. Cu(SO₄) stress increased proline (35%) and catalase (37%) activity but reduced protein (65%) and priming increased proline, protein and catalase activity as compared to unprimed under stress and control conditions. In this study, using priming treatment salicylic acid had usually higher germination characteristics and catalase activity, total proteins and proline content in comparison with untreated or control seeds.

Efficient seed germination and rapid and uniform seedling emergence are important in commercial agriculture. Therefore, the use of strategies to improve germination and seedling establishment is necessary for increasing productivity. Hydropriming has been suggested as a simple pre-germination strategy to improve seed performance. In this study, the effects of different durations of hydropriming (10, 24, 48 and 72 hours) at different temperatures (10 and 25 ˚C) compared to unprimed seeds on the vigor and germination performance of five milk thistle accessions (Ahvaz, Sari, Esfahan, Dezfol and Gachsaran) were evaluated. An experiment was conducted as a factorial experiment based on a completely randomized design with three replications. Germination performance was evaluated by final germination percentage, mean daily germination, mean germination time, the coefficient of germination, Timson's index, time to reach 50% the final germination percentage, germination value, coefficient of uniformity of germination, length and dry weight of seedlings and vigor index. The results show that germination capacity, germination rate and seedling vigor indexes increase significantly in hydro primed seeds at a temperature of 10˚C, whereas a decrease in hydro primed seeds at a temperature of 25˚C. Our results also show that the efficacy of hydropriming on seedling emergence and vigor traits depends on the priming duration and temperature. Hydropriming at 10˚C indicated the most effective on germination indicators and seedling vigor when compared to unprimed seeds. In addition, the comparison of germination and growth indicators in different durations of hydropriming in five milk thistle accessions indicated that the best duration of hydropriming for Ahvaz and Gajsaran is 72h, for Sari and Dezfol is 48 and 72h and for Esfahan is 10 and 24h. Therefore, the effect of hydropriming on germination performance and seedling vigor depends on plant association and hydropriming time and therefore, the selection of the best condition for hydropriming will improve the seed germinability and vigor.