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Showing 9 results for Malek

Somayeh Malekzade, Seyfollah Fallah2,
Volume 1, Issue 2 ((Autumn & Winter) 2015)

In order to investigate the effect of priming techniques on germination parameters of ajowan (Carum copticum L.) seed, an experiment was conducted in completely randomized design with four replications. The experiment treatments included a control (no priming), three hydropriming levels with distilled water (24, 36, and 48 h), three osmopriming levels with PEG (solutions with osmotic potential of -4, -8 and -12 bar), three hormone priming levels with GA3 (50, 100 and 150 ppm), three halopriming levels with KNO3 solution (2, 3, and 4%) and three zinc sulfate levels (0.1, 0.2 and 0.3 %). The results showed that priming treatments had a significant effect on all traits. The rate and percentage of germination were declined in some priming treatments compared to control. Radicle length and root dry weight were decreased in polyethylene glycol -8 bar. Polyethylene glycol -4 bar and 24h hydropriming treatments significantly decreased shoot length and allometry coefficient. However, the treatment of 100 ppm hormone priming significantly increased these traits. Hydropriming 24 h treatment significantly increased germination rate, percentage and seed vigor, but hydropriming 48 h significantly increased radicle and shoot length compared to control. In conclusion, according to the priority of germination or radicle, shoot growth and seed priming cost as well, the hydropriming 24 or 48 h can be recommended as most appropriate priming type for ajowan seeds.

Saeideh Maleki Farahani, Alireza Rezazadeh, Mahdi Aghighi Shahverdi,
Volume 2, Issue 1 ((Spring and Summer) 2015)

In order to investigate the effect of an 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, the Shahed University of Tehran in 2012. In the first experiment, for the seeds of zero, 10 and 30 min exposure to electromagnetic field intensity was 88 microTesla. 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 the 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 causes a significant decrease in the number 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.

Mozhgan Maleki Narg Mousa, Hamidreza Balouchi, Mahmood Attarzadeh,
Volume 2, Issue 1 ((Spring and Summer) 2015)

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, respectively) were shown in urea priming and the lowest (52% and 2.31 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.

Keyvan Maleki, Elias Soltani, Iraj Alahdadi, Majid Ghorbani Javid,
Volume 6, Issue 2 ((Autumn & Winter) 2020)

Extended abstract
Introduction: Conditional dormancy (CD) is a dynamic state between dormancy (D) and nondormancy (ND). Seeds at the conditional dormancy stage germinate over a narrower range of temporal conditions. Conditional dormancy is usually observed in seeds with physiological dormancy. However, primary conditional dormancy has also been seen in some freshly harvested seeds. The purpose of the present study was to investigate whether freshly harvested oilseeds have non-dormancy or conditional dormancy.
Materials and Methods: A factorial experiment was conducted based on a completely randomized design with four replications at Seed Technology Laboratory of Aburaihan Campus, University of Tehran, Iran, in 2018. In this experiment, seeds of rapeseed were collected from 20 different locations in Golestan and Mazandaran provinces. Following that, a germination test was carried out at different temperatures (5, 15, 20, 30, 35°C), and the germination percentage and seed germination rate were recorded. In order to break seed dormancy, two treatments were used: gibberellic acid and after-ripening. For after-ripening treatment, seeds were stored in a paper bag in a dry and dark environment for 6 months. For gibberellic acid treatment, a solution of 100 parts per million (PPM) of gibberellic acid was prepared and added to the Petri dishes. Subsequently, the percentage and rate of germination were recorded.
Results: The results showed that freshly harvested seeds had primary conditional dormancy and germinated in a narrow range of temporal conditions. In addition, cardinal temperatures for freshly harvested seeds were 4.45 and 27.8 for bases and ceilings, respectively. Following gibberellic acid and after-ripening treatments, seeds germinated in a wider range of temperatures and base and ceiling temperatures reached 1.74 and about 40°C, respectively. Thus, germination percentage of seeds treated with gibberellic acid and after-ripening increased at both high and low temperatures. However, the increase in germination percentage was higher at high temperatures than low temperatures. In addition, the effect of gibberellic acid treatment was more than that of after-ripening treatment on the release of dormancy, and after-ripening treatment had an intermediate effect between the gibberellic acid and freshly harvested seeds.
Conclusion: Based on the results of this experiment, the application of gibberellic acid and after-ripening treatments resulted in breaking the dormancy of freshly harvested seeds and increased germination temperature range at high and low temperatures.  Of the two treatments, gibberellic acid had the greatest effect on breaking dormancy and increasing temperature range. Among the cultivars, these changes were maximum in the germination capacity of Hyola 50 and Trapar cultivars and Trapar cultivar had minimum changes.
1-Conditional dormancy of oilseed cultivars was investigated under different environmental conditions.
2-Application of gibberellic acid and after-ripening treatments resulted in breaking primary conditional dormancy in oilseed cultivars.

Mohsen Malek, Farshid Ghaderi-Far, Benjamin Torabi, Hamid Reza Sadeghipour,
Volume 6, Issue 2 ((Autumn & Winter) 2020)

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

Mohsen Malek, Farshid Ghaderi-Far, Benjamin Torabi, Hamidreza Sadeghipour,
Volume 7, Issue 1 ((Spring and Summer) 2020)

Extended Abstract
Introduction: Seeds, like other materials, are hygroscopic and exchange moisture with their surroundings. The changes in the moisture of seeds during storage depend on their hygroscopic nature and this feature plays an important role in determining the seed quality and longevity. Furthermore, studying the hygroscopic characteristics if seeds can be useful in seed storage studies as well as in commercial applications such as drying and seeds processing. Therefore, in this study, the relationship between seed moisture content and relative humidity in seed of rapeseed cultivars was studied.
Material and Methods: In this study, the relationship between the ambient relative humidity and seed moisture content of three rapeseed cultivars at 10, 20 and 30 °C was investigated using hygroscopic equilibrium curves. Therefore, water desorption and absorption curves were studied separately. Water absorption and desorption curves were obtained by drying the seeds at 1% relative humidity and seed hydration at 100% relative humidity, respectively, followed by transferring the seeds to different relative humidities at different temperatures and finally determining the equilibrium moisture content of the seeds. It should be noted that glycerol and sulfuric acid solutions were used to creation different relative humidity. Finally, the relationship between seeds moisture content against the relative humidity was quantified by fitting the D’Arcy-Watt equation.
Results: The results indicated that the seeds moisture content varied in cultivars and temperatures at different relative humidities. Also, there was a difference between water desorption and absorption curves in all cultivars and temperatures; desorption curves were generally higher than water absorption curves. The greatest difference among the cultivars regarding seed moisture content was observed at 100% relative humidity, and this difference was less severe at lower relative humidities. Also, the highest seed moisture content of rapeseed cultivars was observed at 20 °C and 100% relative humidity, and the lowest seed moisture content was recorded at 30 °C and 1% relative humidity.
Conclusions: According to the results, it was found that the relationship between seed moisture content and relative humidity followed a sigmoidal function, and this relationship would also vary depending on cultivar and temperature. There was also a difference between the adsorption and desorption curves, which is called "hysteresis", and showed that the seed moisture content at a constant relative humidity was generally higher in the state of dehydration compared with that in the state of hydration. Due to this event, desorption curve is situated higher than the absorption curve.

  1. Response to hygroscopic equilibrium curves in seeds of different rapeseed cultivars was compared.
  2. Sulfuric acid and glycerol solutions were used to create different relative humidity.

Hakimeh Rahimi, Mohsen Malek, Farshid Ghaderi-Far,
Volume 8, Issue 2 ((Autumn & Winter) 2022)

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.

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.

Mohsen Malek, Farshid Hassani, Enayat Rezvani Khorshidi, Ali Shayanfar, Bita Oskoee, Abbas Dehshiri,
Volume 9, Issue 1 ((Spring and Summer) 2022)

Extended Abstract
Introduction: Galbanum is one of the most important native medicinal plants in Iran, and nowadays the use of its products and derivatives has become widespread in various industries. Thus, the excessive harvest of this species within its natural habitats has increased. Therefore, the species is enlisted as prone to extinction. Due to the lack of information about germination behavior and dormancy alleviating or breaking methods of Galbanum seeds, less attention has been paid to this plant species by seed science researchers. Hence, this study was designed and performed to investigate the effects of different treatments on Galbanum seed dormancy-breaking.
Materials and Methods: In this study, two Galbanum seed populations were collected from Boyer-Ahmad pastures (Iran, Kohgiluyeh and Boyer-Ahmad Province) and Pakan Bazr Isfahan Company (Iran). Seeds were exposed to a cold stratification test for 120 days and germinability and dormancy breaking responses were studied. Also, seed drying effects on germinability after exposure to stratification treatment were investigated to evaluate the practical aspects of this treatment. The impacts of different hormonal pre-treatments including gibberellic acid (GA3) and cytokines (Kinetin, 6-Benzylaminopurine) at different concentrations on germination and dormancy behaviors were investigated so as to assess the effect of these treatments on seed dormancy breaking.
Results: Results showed that germination/dormancy behaviors of Galbanum populations were different and also the effect of different treatments on seeds germination and dormancy varied. An increase in germination was observed when stratification was applied for up to 60 days on two seed populations, thereafter germination decreased by prolonged stratification. Also, it was revealed that desiccation of the treated seeds after stratification reduced seed germination. Examining the cause of this issue revealed that the most important reason for the decrease in seed germination in long periods of stratification was the germination of seeds in the stratification bed and in other words, the difference in seed dormancy levels in different stratification periods. Seed germination behavior and dormancy breaking were improved significantly in both Galbanum populations when the different concentration of gibberellic acid and cytokinins was used.
Conclusion: The results of this study indicated the existence of different levels of seed dormancy in different Galbanum populations. It was also found that cold stratification and hormonal pre-treatment of seeds can be significantly effective in seed dormancy breaking. Eventually, it was concluded that Galbanum seed dormancy was classified as semi-deep and deep morphological dormancy due to the effects of different treatments.

  1. The effect of cold stratification treatments over long periods was investigated on Galbanum seed germination behaviors for the first time.
  2. The desiccation of treated seeds under different cold stratification periods was studied on the germinability of Galbanum seeds for the first time.
  3. AUC (Area under the curve) index was introduced as a practical index in seed dormancy breaking comparison for the first time in domestic research.

Arezoo Paravar, Saeideh Maleki Farahani, Alireza Rezazadeh,
Volume 9, Issue 2 ((Autumn & Winter) 2023)

Extended abstract
Introduction: Lallemnatia ibercia (Dragon’s head) is an annual herb, which belongs to the Lamiaceae family. Nowadays, its seed is widely used in food and pharmaceutical industries due to its high mucilage and oil content. Soil moisture, nutrition, light, and temperature of the maternal environment play an important role in plant growth. However, the effect of soil moisture on yield and seed quality indices is greater during seed development. The positive effects of maternal plant nutrition with mycorrhizal inoculation can influence the quality improvement of the seeds developed under water deficit conditions. The reason for the quality improvement of the seeds developed under mycorrhizal inoculation condition is reported to be their water balance under water deficit conditions and as a result, more absorption of water and nutrients. Nutrient uptake by the maternal plant can play an important role in improving the germination and quality characteristics of the seeds developed under drought stress.
Materials and Methods: A field experiment was conducted in a completely randomized design with three replications at the Seed Science and Technology Laboratory of the College of Agriculture, Shahed University during f 2018-19 and 2019-20 years. Experimental treatments included irrigation regime (30, 60 and 90% of depletion of available soil water (ASW)) and mycorrhizal inoculation (non-inoculation and inoculation).
Results: The results showed that a reduction in soil moisture in the maternal environment decreased germination percentage and seed quality.  Germination percentage (51.20%) germination rate (7%), seed vigor index (27.70%), seedling length (28.3%), seedling dry weight (34.80%), seed mucilage (75.40%), as well as seed nutrients (27.30%), seed oil (14.60%) and catalase (35.25%) and ascorbate peroxidase (25.70%) enzymes activities enhanced in the seeds developed under 60% depletion of available soil water and application of mycorrhizal compared to control (30% depletion of available soil water and without mycorrhizal). Compared with the 30% depletion of available soil water and without mycorrhizal, mean germination time (17%) and lipid peroxidation (41.10%) increased under the 90% depletion of available soil water and without fertilizer mycorrhizal.
Conclusions: According to the results of this study, the irrigation regime of 60% available soil water depletion of maternal plants leads to the reduction of seed quality. However, the nutrition of maternal plants by mycorrhizal inoculation effectively improved the quality of seeds developed under water deficit due to the absorption of water and nutrients.

  1. Germination and seedling growth indices, quality and biochemical characteristics of the Lallemantia iberica seeds developed under different conditions of irrigation regime were investigated.
  2.  The effect of mycorrhiza on nutrient uptake, oil content, and antioxidant enzyme activity of the seeds developed under different irrigation regimes was investigated.
  3. The extent of damage to the lipid structures of cells in the seeds developed under different irrigation regimes and mycorrhiza fertilizer was investigated.

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