نشریه پژوهش های بذر ایران
سال دوم شماره 1 (پیاپی 3، بهار و تابستان 1394)

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 were 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 to 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.

In order to investigate the effects of priming with KH2Po4 solution on emergence and heterotrophic growth of black cumin (Nigella sativa L.) seedling a series of experiments were conducted at the Faculty of Agriculture، Ferdowsi University of Mashhad، Iran، in 2013 and 2014. A field experiment was conducted as factorial layout based on a randomized complete block design with four replications. The fertilizer resources (vermicimpost (V) +Tiobacilus (T)، micronized Sulfur (S) +T، V+S+T and control) and three levels of phosphorus (0، 30 and 60 kg. ha-1) were the first and second experimental factors، respectively. In the second experiment، selected treatments (in which showed emergence below 60% in the previous experiment) and seed priming (no priming، hydro priming and three levels of phosphorus (P) -priming as 100، 300 and 500 mM KH2Po4) were the first and second experimental treatments، respectively. Based on the results، the resources of soil amendment (V+T and V+S+T) significantly increased the emergence percentage of black seed (by 50 and 54%، respectively). In addition، seed reserve depletion percentage، seed reserve utilization efficiency and emergence percentage significantly increased by 300 mM KH2PO4 (by 9، 143 and 29%، respectively). There was a significant positive relationship between the weight of mobilized seed P and the emergence percentage of black seeds (R2= 0. 90 **).

Seeds of seven species of medicinal plants collected from the natural habitat in Lorestan province in the summer 2011. Germination test carried out in a completely randomized design with four replications of 25 seeds in H2O. Species of Smyrnium cordifrolium، Kelussia odoratissima، Dorema aucheri and Ferulago angulata had no germination while Heracleum persicum، Bunium luristanicum and Falcaria vulgaris showed germination of 30، 96 and 97% respectively. Different treatments of breaking dormancy applied to the species with germination below 30% [moist-chilling for periods of 2، 4، 6، 8، 10 and 12 weeks، with two concentrations of 250 and 500 ppm of gibberellic acid، a combination treatment (gibberellic 250 ppm + 4 weeks moist-chilling and gibberellic acid 500 ppm + moist-chilling for 4 weeks) and potassium nitrate 2 g/l]. The results showed that moist-chilling was the most effective treatments to break seed dormancy of Heracleum persicum (6 weeks)، Dorema aucheri (12 weeks)، Kelussia odoratissima (12 weeks) and Ferulago angulata (12 weeks). Therefore، based on their reactions to the treatments، dormancy of Kelussia odoratissima and Ferulago angulata could be classified as deep physiological dormancy and species of Dorema aucheri and Heracleum persicum intermediate physiological dormancy type.

Due to importance of medicinal plants، understanding the seed germination response to temperature is agronomically important. A laboratory study was conducted to investigate the effect of different temperatures on seed germination of fennel، cannabis and sesame in a completely randomized design with four replications. Various constant temperatures (5، 10، 15، 20، 25، 30، 35 and 40° C) were considered. According to the results، the effect of temperature on germination rate and percentage in all species was significant. The seeds of fennel were not germinated in 5، 35 and 40 0C and seeds of sesame germinated only in 5 0C. Maximum rate of germination obtained in 30 °C for fennel and 25 °C for sesame and cannabis. The highest germination percentage of fennel، and cannabis and sesame were in 20، 25 and 30 0C respectively. The lowest of germination uniformity (GU) were observed in 20 0C for fennel and in 15 0C for cannabis and sesame. Amount of seedling vigor maximized for fennel and cannabis in 250C and for sesame in the 300C. The values of length and weight of radical and plumule were enhanced with increase of temperature and record on maximum in special temperature and then reduced slowly. The quantitative information provided by this study can be used in prediction of emergence under diverse temperature conditions. Germination of cannabis seeds occurred in a wide range of temperatures and this seed are less sensitive to temperature compared to the other two plants. Germination of fennel seeds was less، except at 200C. The sesame seeds had good germination at 15-35 0C.

The effect of spermidine on seed germination of three different cucumber cultivars under cold stress was studied as a 4×2 factorial experiment by using a completely randomized design with 4 replications. First factor was 4 concentrations of spermidine consisted of 0 (control)، 0. 1، 0. 5 and 1 mM and the second one was three cucumber cultivars consisted of ‘Emperator’، ‘Amiran’ and ‘Rashid’. For this purpose، 50 seeds of each cultivars were placed on filter papers inside steriled petry dishes and spermidine solutions were added to them according to each treatment. All petry dishes were placed in a 13°C temperature of the incubator until end of the experiment and germinated seeds were counted daily. The measured traits were percentage of germination، plumule length، radicle length، dry and fresh weight of the plumule and radicle. The results showed that treating seeds of ‘Rashid’ cultivar with 0. 1 mM spermidine increased percentage of germination، plumule and radicle length، fresh and dry weights of radical compared with control. Treating ‘Rashid’ seeds with high concentration (1 mM) of spermidine showed inhibitory effects on all measured characteristics، but in ‘Amiran’ cultivar only decreased percentage of germination، plumule and radicle length، fresh and dry weight of ridicle.

Bilhar or Mountain Kandall (Dorema aucheri) belongs to Apiacea family that contains flavonoid and coumarine compounds. Since، propagation of this plant in natural habitats occurs through seed and due to deep dormancy، the identification of different seed dormancy breaking methods is necessary for preservation of this species. In this respect، different methods، including chilling، washing and gibberellic acid was studied، on the seeds gathered from Kohgiloyeh and Boyerahmad province. For this reason، a factorial experiment with three factors was done based on completely randomized design in three replications، in the faculty of agriculture، Yasouj University، on 2012. Experimental factors were included، chilling period (stratification periods of 3 and 4 weeks)، gibberellic acid (zero and 1500 ppm) and washing (washing with distilled water and non-washable). Results showed that 4 weeks chilling treatment had maximum germination percentage and germination rate and seedling vigor. Also maximum root and shoot dry weight was obtained from the seeds of this treatment. Whereas، double and triple interaction effects for germination percentage، epicotyl and hypocotyl length were not significant. Germination percentage was better in 4 weeks prechilled seed than 3 weeks. Obtained results from this research showed that Bilhar seeds have the physiological dormancy.

Germination rate and percentage are maximal at optimum temperatures and then reach to zero at the base and ceiling temperatures. An experiment was conducted at the Gonbad Kavous University laboratory as a completely randomized design with 4 replications، to study germination response to temperature and evaluation of cardinal temperature on germination rate and percentage of hibiscus tea. Seeds germinated at 0 to 45 degrees Celsius by 5 degree intervals. Results indicated that the response of germination percentage and rate adequately fitted with dent like and segmented functions، continually. Base and ceiling temperatures were 1. 66 and 43. 33 degree Celsius for germination percentage and 4. 53 and 42. 95 degree Celsius for germination rate. Optimum temperatures were 30 degree centigrade for germination rate and 11. 56 and 33. 63 degrees Celsius for germination percentage. In conclusion، base and favorable temperatures for hibiscus tea seeds were 11 and 350C. Therefore it is recommended to cultivate in the weather condition of Gonbad kavous.

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 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 on 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 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 Vali-e-Asr University of Rafsanjan. Experimental factors included level 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.

In order to investigate the effect of electromagnetic field and ultrasonic waves on the seed germination of Cuminum cyminum that two separate experiments using a completely randomized design with four replications was conducted at Seed Science and Technology Laboratory of Faculty Agricultural Sciences، Shahed University of Tehran in 2012. In first experiment، for the seeds of zero، 10 and 30 min exposure to electromagnetic field intensity was 88 micro Tesla. In the second test (ultrasonic waves)، seeds for zero، 2، 4، 6، 8 and 10 min exposure ultrasonic waves’ intensity were 40 and 59 kHz. The interaction between electromagnetic field and the length had a significant effect on the traits of length، fresh weight and dry weight of root and shoot، length and weight of root to shoot ratio، percent and rate germination and mean germination time. In most of the studied traits showed that electromagnetic field cause significant decrease in the amount of traits، so that the control (zero M. T) had the highest value. The interaction of Ultrasonic waves at the time had a significant effect of on the most traits. Maximum germination percentage (100%) for the treatment of 40 kHz with duration of 4 and 6 minutes and mean germination time was highest in control (10. 76 days) and 59 kHz treatment duration of 2 and 4 min (respectively 11. 01 and 10. 75 days). Generally Cuminum cyminum seeds responded positively to the use of ultrasonic waves (In contrast field) and germination index was significantly increased in this case.

In order to study، the effects of hydropriming and osmopriming on germination characteristics of Nigella sativa L. under salt stress an experiment was conducted in factorial laid out in completely randomized design with four replications at Research Laboratory، Faculty of Agriculture، Mashhad Branch، Islamic Azad University-Mashhad Iran، in 2014. Factors were included of priming treatment in six levels [control (Non-priming)، hydropriming with distilled water، osmopriming with KNO3، KCl، CaCl2 and NaCl] and salinity treatment in four levels [0، 50، 100 and 150 Mmol]. Analysis of variance showed that the effects of salinity and seed priming on all measured indices and interaction between two factors on germination percentage and rate، radicle and plumule length and seed vigor were significant at the probability level of 1%. The results showed that with increasing salt concentration all measured traits were decreased. This decreasing started from the 50 Mmol concentration. Under salt stress condition، osmopriming with KNO3 and then hydropriming and osmopriming with KCl improved all germination indices compared with control.

Rocket (Eruca sativa) is an important medicinal plant which not be done any experiment about its germination quantification response to temperature. Thus، an experiment base on CRD performed in seed research laboratory of Urmia University with four replications with ten levels of temperatures includes: 1، 3، 5، 10، 15، 20، 25، 30، 35 and 40 0C. Results revealed that the temperature had significant effects on the rate and germination percent and Dent-like model estimated greatly cardinal temperature (base، upper and bottom optimum and ceiling temperatures). Germination rate stopped at equal and less than 0. 79 and equal and higher than 47. 6 0C and rmax were 0. 066 in 16. 9-32. 6 0C. Also، results emphasized that Rocket seed needs low temperature for germination but، germination rate and percent of Rocket increased by temperature increment. Therefore، the Rocket can germinate and emerge in dispersal spans of an environmental thermal from 0. 79 to 47. 6 0C and thus recognized as a crop with allowable production for various seasons and climate.