farzad sharif zadeh

In order to improve seed germination under environmental stress conditions such as salinity, one of the solutions is to use seed priming. Despite this advantage of priming, the longevity of primed seeds usually decreases and it has been observed that using post-priming treatments such as heat shock can improve the longevity of primed seeds. This research investigates the effect of seed priming with salicylic acid, methyl jasmonate, and brassinosteroid under salinity stress and the effect of heat shock after priming on improving the longevity of primed seeds.

The effect of seed priming with hormonal substances such as methyl jasmonate at three concentrations of 1, 100, and 1000 micromolar and brassinosteroid at three concentrations of 25, 75, and 100 mg/liter on increasing the seed germination traits of Suaeda fruticosa was investigated under salinity stress during separate experiments. In both studied hormones, priming temperatures of 5, 10, and 15°C were used for 1 and 2 days. Hormonal seed priming with salicylic acid at a concentration of 25 mg L-1 for 2 days at 10°C -obtained from the previous results (unpublished)- was used for comparison with those of the studied treatments. To determine the most suitable accelerated aging stress for evaluating and determining the best heat shock treatment, the accelerated aging test of seeds was carried out for two, four, six, eight, and ten days. In this research, to improve the longevity of primed seeds, they were exposed to heat shock treatment at temperatures of 30, 35, and 40°C for 1, 2, 3, and 4 hours after seed priming.

Both seed priming treatments with methyl jasmonate and brassinosteroid significantly increased all the tested germination traits compared to the control (without priming). This increase in traits such as germination percentage, vigor index, and seedling length in seed priming with methyl jasmonate was 46.4%, 67%, and 41%, respectively, and in the case of priming with brassinosteroid was 32%, 44%, and 38%, respectively. Also, in this research, the heat shock treatment at 40°C for four hours after priming had a significant and positive effect on seed germination. Application of the mentioned treatment increased germination by 60% at the end of the aging period compared with the control (without the application of heat shock).

Despite the significant increase in germination percentage by each of the hormonal substances like methyl jasmonate and brassinosteroid, the comparison of the best treatment combination of these substances with salicylic acid showed that seed priming with 25 mg L-1  of salicylic acid for two days at 10°C caused a significant increase in the percentage of germination under salinity stress. Also, the heat-shock post-priming treatment significantly improved the longevity of primed seeds.

Currently, temperature and salinity stresses are spreading globally, which have a detrimental impact on the performance of various plants, particularly during seed germination and seedling growth stages. Therefore, the objective of this laboratory study was to examine the influence of temperature treatments and salinity levels on germination characteristics and initial seedling growth of kochia.

In the first experiment, temperature at nine levels (1, 5, 10, 15, 20, 25, 30, 35, and 40°C), and in the second experiment, salinity (osmotic potential at six levels (no stress, -0.4, -0.8, -1.2, -1.6, and -1.8 MPa) were considered as experimental treatments. In order to determine the cardinal temperatures (base, optimal, and ceiling) of germination in kochia seeds, non-linear regression models including the segmented, dent-like, and modified beta models were used.

In the first experiment, the response of kochia germination rate was predicted by a segmented function with R2, RMSE, and AIC (Akaike) values of 0.92, 1.32, and 65.69, respectively, which indicates the high accuracy and precision of this model in predicting the cardinal temperatures of kochia seed germination compared with the other two models. In this model, the estimated base temperature for germination was 0.7°C, the optimal temperature was 20°C, and the ceiling temperature was 44.3°C. In the second experiment, salinity stress negatively affected the characteristics of seed germination in kochia, including germination percentage, germination rate, percentage of normal seedlings, seedling length, and seedling vigor index. The highest germination percentage of kochia seeds was observed under salt-free conditions with 88.66%, which decreased to 13% under -1.8 MPa salinity conditions.

In general, the results showed that the segmented model is more efficient and accurate than the other two models in predicting germination of kochia seeds under different temperature treatments. Also, increasing levels of salinity stress significantly reduced germination potential and seedling growth of kochia seeds, so that at a stress level of -1.8 MPa, germination rate decreased by 75% compared with stress-free condition.

Linseed (Linum usitatissimum L.) is a multipurpose crop and is cultivated to obtain oil, fiber, and seeds. Under optimal moisture conditions, the temperature is considered an environmental factor affecting the germination of this crop. Hence, knowing the cardinal temperatures can help farmers to predict the successful germination, emergence, and even yield of linseed and help scientists to develop new cultivars that are more tolerant to high temperatures. Therefore, this study was performed to determine the temperature range and the cardinal temperatures of germination in two linseed genotypes.

The germination response of two linseed genotypes (Golchin genotype and Line 286) to nine temperatures (3, 5, 10, 15, 20, 25, 30, 35, and 40 Celsius degrees) was quantified in a CRD based split-plot experiment with four replications. For this purpose, three nonlinear regression models (beta, segmented, and dent-like) were used to fit to the data and select the superior model. The superior model was selected using the Akaike information index (AIC), the modified Akaike index (AICc), and ∆i.

Findings showed that the beta model had the best performance in estimating the line 286 cardinal temperatures according to its lower AIC (-3.96), AICc (-89.61), and ∆i (0). Accordingly, the base, optimum, and maximum temperature as well as the number of biological hours estimated by this model for Line 286 were 7.18, 24.22, 40.16 Celsius degrees, and 19.25 hours, respectively. In the Golchin genotype, the beta model with the lowest AIC=-3.89 and AICc= -89.083 fitted better compared with the other models. Nonetheless, considering ∆i for beta which was respectively 0, 1.61, and 4.49 for beta, segmented, and dent-like models, Beta and segmented models had a similar accuracy in estimation of cardinal temperatures for Golchin genotype. These findings represent that the suitable temperature range for germination of the Golchin genotype is 3.8- 23.85 Celsius degrees and the range of biological hours to 50% of germination varied from 16.42 to 19.77 hours.

Overall, according to the results of this study, it is possible to predict the time to germination under optimal moisture conditions using the beta model for Line 286 and one of the two beta and segmented models for the Golchin genotype.

Highlights:

1. A suitable model was developed for a suitable prediction of the seed germination percentage of two linseed genotypes (Golchin genotype and Line 286).
2. The cardinal temperatures for two linseed genotypes (Golchin genotype and Line 286) were determined.

One of the main problems for the doctrine of the traditional view of hell is Proportionality objection. It claims that eternal punishments for finite crimes of human beings cause undue harm and therefore are incompatible with divine justice. The proportionality principle states that the degree of punishment that a person justly merits must be proportionate to the level of his wrongdoing. One of the common ways to respond to this objection is rejecting the retributive nature of hell. Morteza Motahhari denied retributivism by distinguishing between the criminal system of the world and hereafter. He believed punishments in hell are identical to human deeds and they are nothing more than spiritual aspect of them. Regarding this view which is called 'Self-imposed punishments', God is not the punisher of the sinners, and the residents of hell suffer from their sinful actions. This paper begins with examining Motahhari's metaphysical theory of punishment as a theodicy of hell. Then I will discuss a modal argument against his theory. I shall argue there is not a necessary correlation between crimes and punishments. My conclusion is that Motahhari's theodicy would be undermined God's moral perfection either therefore it does not get God off the moral hook.

Stipagrostis pennata is one of the most important desert species to cover desert areas as well as to bind the sand which unfortunately cannot produce the best quality seed for its survival. This research was conducted to callus induction and experimental treatments included two types of explants (stem and seed), four various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) consists of 1, 2, 3 and 4 mg /L and five levels of 6-benzylaminopurine (BAP) consists of 0, 0.05, 0.1, 0.2 and 0.4 mg /L were applied to the Murashing and Skoog basal media. This study was conducted as a factorial experiment based on completely randomized design with three replications. Results showed a significant interaction effect among explants, auxin and cytokinin on the traits related to callus induction. Seed explant showed the maximum of callus induction percentage (100%) in medium containing 3 mg/l 2,4-D with both 0.4 or 0.2 mg/l of BAP. The highest percentage of callus induction in stem node explant (60%) was obtained in 3 mg/l 2,4-D with 0.4 mg/l BAP treatment. For the surface and fresh weight of callus in both explants and the volume of callus in seed explant, 3 mg/l 2,4-D with 0.4 mg/l BAP was recognized as the best treatments. Stem node explant in the of 2 mg/l 2,4-D with 0.1 mg/l BAP treatment showed the highest volume of callus. In general, the use of seed explant in mg/l 2,4-D and 0.4 mg/l BAP treatment can be introduced as an optimized protocol.

According to numerous reports about the global warming process and the fluctuations of rainfall, the study of climate change, especially in semi-arid regions of the country's dryland, is necessary in order to adapt to this phenomenon. The purpose of this study was to investigate the current process of climate change and the projection of CMIP5 (Coupled Model Intercomparison Project Phase 5) climate models under the CORDEX (Coordinated Regional Climate Downscaling Experiment) project in dryland areas of Kurdistan province. In this study, Sanandaj, Qorveh, and Zarineh stations were selected as the nearest synoptic meteorological stations to the agricultural research institutes of dryland in Kurdistan province. At first, bias correlation was done on downscaled data of the CORDEX project. Given that the future course of the project began in 2006 and continues until 2100, the data were divided into four time periods. The forecasted climatological data were compared with the observed data from 2006 to 2017, then the projection of climate models in the future periods was considered. The trend of climate change in the past, using the Mann-Kendall test and the Sen’s slope estimator, indicates a decrease in precipitation and an increase in temperature and potential evapotranspiration. The comparison between predicted and observed data during 2006-2017 showing the high accuracy for temperature and evapotranspiration estimation, and low accuracy for rainfall estimation. Also, according to the projection of climate models at the end of 21st century, temperature and evapotranspiration increase in all climatic models of all stations and fluctuations in rainfall are projected. While precipitation reduction in Sanandaj is expected, more precipitation will occur in Qorveh and Zarineh stations.

Hyparrhenia hirta L. is a drought tolerant herbaceous species and one of the valuable genetic reserves. Poor seed production has caused some problems related to natural regeneration of this plant and micro-propagation and the production of artificial seeds through somatic embryos in this plant is necessity and especially important. A factorial experiment based on a completely randomized design with three replications was performed to consider the effect of encapsulation of somatic embryos with different concentration of sodium alginate and calcium chloride as well as different duration of ion exchange on seedling emergence percentage from encapsulated embryos. Single adult embryos derived from suspension cultures were placed in different sodium alginate concentrations of two, three and four percent. Single embryos in sodium alginate solution were injected by syringes in various calcium chloride complex at concentrations of 50, 75 and 100 mM, and were coated in different times of 20, 30, 40 and 50 minutes. The encapsulated seeds were cultured on MS 1​​/2 without any growth regulator and kept in a growth chamber at 22 °C and the period of 16/8 h (light/darkness) for two weeks and the emerged seedlings from the alginate coating were measured. The highest germination percentage and seedling emergence (60%) was obtained from 3% sodium alginate and 100 mg calcium chloride during 40 minutes of ion exchange time.

The objective of this research was to evaluate the effect different temperatures on germination and determine cardinal temperatures (base, optimum and maximum) of Secale mountanum at temperatures of 3, 5, 10, 15, 20, 25, 30 and 35 oC. Three nonlinear regression models (segmented, dent-like and beta) was used for quantifying response of germination rate to temperature. Results showed that the different temperatures were effect on germination percentage and germination rate. According to the root mean square of errors (RMSE) of germination time, the coefficient of determination (R2), the simple linear regression coefficients a and b, and the relationship between the observed and the predicted germination rates the best model for determination of cardinal temperatures of Secale mountanum was dent-like and beta models. Base, optimum and maximum temperatures were estimated about 2.70 to 3.17, 21.27 to 30.00 and 35.00 to 35.05°C, respectively with this model. However, due to the above SE for temperature base and negative estimate the base temperature of beta model can be reported the dent-like model. Therefore with used of dent-like model and estimated parameters can be used this model for predicting germination.

Breaking seed dormancy is an essential step towards germination improvement in Hordeum vulgare ssp. spontaneum. This study was conducted to evaluate the effects of physical, chemical, hormonal and stratification treatments on Hordeum spontaneum seed dormancy. In the current research two highly dormant genotypes of Hordeum spontaneum (TN1350 and TN951) were evaluated. To this purpose, 25 seeds in four replications were placed in 9 cm petri dishes containing filter paper saturated with distilled water (control), chemical or hormonal solutions. To induce the stratification treatments, seeds were kept in 35˚C (heat stratification) or 5˚C (cold stratification) for periods of 2, 4, 6 and 8 weeks. Results indicated that heat stratification increased germination significantly. Germination percentage of seeds under 35˚C treatments increased since the second week of treating and reached the maximum in the fourth week (47.5% in TN951 and 86.25% in TN1350). Results showed that GA3 in all used concentrations was the most effective hormone in inducing germination compaired to other used hormons in this study. The highest germination percentage in Hordeum spontaneum seeds was observed in 100 mg/l GA with increased germination percentage up to 68.75% in TN1350 and 31.25 in TN951. Results of this study revealed that seed dormancy in Hordeum spontaneum can be overcomed by GA3, and heat stratification. On the other hand, seed dormancy was apparently deeper in the genotype with darker seeds)TN951(which were also less affected by after ripening treatments.

Seed priming is one of the most important techniques used to improve seed germination under biotic and abiotic stresses. For this purpose, germination and seedling growth characteristics of primed seeds of Tall wheat grass (Agropyron elongatum (Host.) P. Beauv) were evaluated under drought and low temperature condition. A factorial experiment was conducted on the basis of randomized completely block design with three factors with four replications. The experimental factors were priming with two levels including urea primed (using urea -4 bar at 10 °C for 36 h) and non-primed seeds; germination temperatures, including 3, 6, 9, 12, 15, 20 and 25 °C; and osmotic potential including zero (distilled water), -3, -6, -9, and -12 bars (applied by polyethylene glycol 6000). Increasing trend have been observed for all germination indices, except mean germination time, with increasing temperature from 3 to 25 °C and seeds revealed the greatest sensitivity to temperatures below 9 °C. However, this trend was reversed with increasing drought stress, the seeds sensitivity to drought stress started from the potential of -6 bar and reached to maximum in -12 bar. However, primed seeds compared to non-primed seeds have demonstrated better germination under both drought and low temperature stresses. The results of this study showed that the highest seedling vigor index and germination rates achieved in the temperature range of 20-25 °C and water potential of zero to -3 bar.

Low seed germination and seedling emergence is one of the main problems in saline areas. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stress. The objective of this research was to evaluate the effect of seed priming with gibberellin، NaCl and water on seed germination and seed reserve utilization and germination of Mountain Rye (Secale montanum) seeds under salinity stress in the Seed Laboratory of Department of Agronomy and Plant Breeding، the University of Tehran، Karaj، Iran. Treatments were combinations of 5 levels of salinity stress (0، -4، -8، -12 and -16 bar) and 4 levels of seed priming and control with 3 replications. Results indicated that with increase in salinity stress، germination components such as germination percentage، germination index، mean time to germination، seedling dry weight of utilized (mobilized) seed، seed reserve utilization efficiency and seed reserve depletion percentage decreased، but seed priming showed lower reduction. The highest germination percentage (85. 3%) was obtained by hydro-priming and halo-priming in control conditions. The highest germination index (42. 2) and the minimum mean germination time (1. 02) were obtained from hydro-priming in control conditions. But in higher levels of osmotic pressures، the highest germination percentage، germination index and the minimum means germination time were obtained from priming with gibberellin. In all of the drought levels، primed seeds possessed more germination rate and seedling dry weight than control. Across salinity osmotic pressures، halo-priming had a greater weight of utilized (mobilized) seed reserve. The highest seed reserve depletion percentage and seedling dry weight were achieved from halo-priming and minimum osmotic pressure. Also، seed priming increased antioxidant enzyme activity during seed germination process. It is concluded that priming results in improvement in germination components of Mountain Rye in salinity stress conditions and increases the resistance of Mountain Rye to salinity stress in germination phase.

Knowledge about genetic diversity is an essential step towards conservation of genetic resources and developing further strategies for plant improvement. The objective of this research was to evaluate the agronomical and morphological traits and determine the level of variation within wild barley ecotypes especially for acclimation traits. In this study 188 ecotypes of wild barley (Hordeumspontaneum) were evaluated for qualitative and quantitative traits in a trial. Evaluated traits in this study included 24 agronomical, phenological, morphological and physiological traits which were measured in the field or laboratory. Different characters showed different levels of diversity based on descriptive statistics and Shannon diversity index. Flag leaf area, and flag leaf weight represented the highest diversity among quantitative traits based on coefficient of variation (CV) in qualitative traits, stem nod color and spike erectness were the most diverse traits. Cluster analysis based on morphological and agronomical traits and the origin of ecotypes were more in line with geographic data. Based on these traits, populations from cold climates were clearly distinguished from desert populations.

Seed dormancy is a temporary failure of a viable seed to germinate. Various methods are used for breaking seed dormancy, depending on plant species and type of dormancy. Three seed populations originated from Esfahan, Semnan and Fars provinces were exposed to different seed dormancy breaking treatments such as mechanical and chemical scarification, humid chilling, GA3 and polyethylenglycol 6000 in order to break dormancy and improve seed germination. Unlike Semnan and Fars populations, Isfahan population did not show a significant positive reaction to treatments. Applying polyethyleneglycol solution of -10 bar for Semnan population and combination of moist chilling and polyethyleneglycol solution for Fars population resulted in the highest germination parameters. Germination percentage reached to 47.97% in Semnan and 64% in Fars population and mean germination time reached to 1.55 and 2.26 days, respectively. Activity of α- amylase and β-1,3-glucanase enzymes in seeds of oregano showed that non-dormant seeds exhibited significantly higher activity than dormant seeds. Different responses of oregano populations to applied treatments showed that intensity of dormancy is related to climate and origin of seeds and differs considerably among populations.

One of the most important oilseed plants in Iran is rapeseed. Seed quality is affected by deterioration and aging during storage. The purpose of this study was to evaluate the roles of various chemicals on the recovery of germination characteristics in deteriorated seeds of rapeseed. In this study, one commercial Brassica napus cultivar (okapi) was used. This experiment had two parts. In the first part, seeds with different moisture contents (5, 9, 13, 17%) were stored in incubators set at five temperatures (5, 15, 25, 35, 45ºC). After 90 days, germination was conducted for these 20 storage conditions. In the second part, deteriorated seeds with high germination percentage (74%), medium germination percentage (47%) and low germination percentage (5%) resulted from following treatments: 9/35, 13/25 and 17/25 (moisture content/ storage temperature), respectively, were treated with various chemicals. These chemicals were gibberellic acid, salicylic acid and ascorbic acid in four levels including control, 25, 50 and 100 ppm. A factorial experiment was conducted in a completely randomized design with four replications. Analysis of variance showed that the main effects of deterioration, chemicals concentrations and their interactions were significant for all measured traits. The best treatment was ascorbic acid with concentration of 100 ppm which increased germination percentage and percentage of normal seedling by 29 and 48%, respectively.