Iranian Journal of Seed Research

Evaluating the initial growth of soybean (Glycine max) seedlings in response to different concentrations of copper compounds in the maternal plant

Sina Fallah

Extended abstract
Introduction: The use of nanotechnology is increasing in many fields including agricultural sciences. Concurrently, the release of these particles into the environment is inevitable, which may have adverse effects on plants. Therefore, it is important to understand the interactions between nanoparticles and crops as an essential component of all agricultural ecosystems. In this regard, a study was conducted on the effects of nanoparticles on germination potential and initial growth of F2 seeds by cultivating soybean in soil containing copper oxide nanoparticles.
Materials and Methods: To evaluate the nourishment effects of maternal soybean with copper compounds on its seedlings, two factorial experiments (in a growth chamber and pot) were conducted in a completely randomized design at the Faculty of Agriculture, Shahrekord University in 2021. Treatments in the maternal plant included different copper compounds (copper oxide nanoparticles with sizes of 25, 50 nm and copper chloride) and five concentrations of copper compounds (0, 50, 100, 200 and 500 mg/kg soil), and the seeds produced from these treatments were evaluated under controlled and pot conditions.
Results: An increase in the concentration of copper chloride and copper oxide nanoparticle (25 nm) in maternal plants reduced the germination percentage (25 and 78%), radicle length (56 and 82%), radicle weight (35 and 81%), plumule length (19 and 71%), plumule weight (32 and 73%) and seedling vigor index (49 and 94%) of produced seeds, respectively. The evaluation of soybean seedlings nourished with different copper compounds also showed the nourishment with copper chloride and copper oxide nanoparticle (25 nm) significantly decreased the content of chlorophyll a (10 and 74%), chlorophyll b (38, 49%), carotenoids (136 and 145%), root length (27 and 61%), seedling height (31 and 58%), leaf area (44 and 64%), and shoot weight (34 and 64%) compared to the control, respectively.
Conclusion: In general, it is concluded that the toxicity of copper compounds in the rhizosphere of the maternal plant for the produced seeds is directly related to the concentration. Therefore, the toxic effects are intensified when the maternal plant is nourished with copper oxide nanoparticles, and the seeds produced under these conditions have poor vigor.

Highlights:
1. Nourishment of the maternal soybean plant with copper oxide nanoparticles reduces the seedling growth of the produced seeds.
2. Reducing the size of copper oxide nanoparticles has a more toxic effect on the germination of produced seeds.
3. The toxic effects of copper oxide nanoparticles continue until the seedling stage.

Effect of seed priming on some germination indices and enzymatic activity of safflower (Carthamus tinctorius) seedling under drought stress in vitro

Seyyed Gholamreza Moosavi

Extended Abstract
Introduction: Safflower is a plant that has been considered due to its high medicinal and nutritional value, especially in the extraction of edible oils in developed countries. Drought is one of the most important harmful factors in arid and semi-arid regions of the world that affects plant production. Modifiers play an important role in plant adaptation to stress conditions. Among these compounds are the hormone gibberellic acid and the antioxidant ascorbic acid, which increase plant tolerance to adverse environmental conditions. The present study investigated the effect of gibberellic acid and ascorbic acid on seed germination parameters and some enzymatic indices of safflower under drought stress.
Materials and Methods: The experiment was conducted as a factorial based on a completely randomized design with three replications in the Agricultural Science Laboratory of Iranshahr University in 2020. Experimental treatments included three levels of control (pretreatment with distilled water), pretreatment with gibberellic acid and ascorbic acid, and four levels of drought stress (0, -3, -6, and -9 bar). Drought stress was applied using polyethylene glycol 6000. Seed germination was carried out inside a germinator at 25 ° ^C for 14 days in darkness. Germination traits and enzymatic indices were measured using standard methods.
Results: The results of variance showed that most germination and growth indices of safflower seedlings decreased with increasing drought stress. Also, drought stress led to changes in the activity of antioxidant enzymes. Seed priming with gibberellic acid and ascorbic acid increased germination indices and seedling growth and improved enzymatic activity, including catalase, peroxidase, and superoxide dismutase in comparison with untreated seeds. Priming with gibberellic acid had a significant advantage. Seed priming in drought stress conditions has increased germination rate, protein content, and catalase, peroxidase, and ascorbic dismutase activity, respectively, compared to the control.
Conclusion: In general, seed priming of safflower using gibberellic acid changed the activity of antioxidant enzymes. These activities ultimately moderated the negative effects of drought stress and increased germination parameters.

Highlights:

The role of gibberellic acid and ascorbic acid on safflower seed germination traits was investigated.

The effect of gibberellic acid and ascorbic acid on the activity of antioxidant enzymes and soluble protein during seed germination was investigated.

Effect of plant growth promoting bacteria and temperature treatments on germination indices and seedling growth of safflower (Carthamus tinctorius)

Amin Salehi

Extended abstract
Introduction: Safflower (Carthamus tinctorius L.) is an annual oilseed crop that is adapted to arid and semi-arid regions and is considered an indigenous plant of Iran. Germination and seedling stage in the soil is one of the most important stages in the life cycle of plants. High germination rate and percentage increase the number of seedlings and the rapid successful establishment of seedlings in the soil also contributes to the suitable vegetative growth of the seedlings in later stages of life. Therefore, evaluation of germination indices and seedling establishment in the soil and finding more suitable conditions to improve these indices can have a direct impact on more successful plant cultivation. One of the methods used in this regard is priming.
Materials and Methods: In order to study the effect of plant growth-promoting bacteria and temperature treatments on germination indices and seedling growth of the safflower, this investigation was conducted based on a completely randomized block design with three replications at the Agricultural Research Laboratory of Yasouj University in 2016. Experimental factors were seven levels of temperature treatments (5, 10, 15, 20, 25, 30, 35°C) and seed priming with three strains of Pseudomonas fluorescens such as Pf 2, Pf 25 and CHA 0 and one strain of Bacillus subtilis and control (without inoculation).
Results: The results showed that 20°C temperature caused the highest germination percentage, germination rate and vigor length. Also, seeds inoculated with Pseudomonas fluorescens growth-promoting bacteria strain CHA0 had the highest germination percentage (68.74), germination rate (3.49 seeds per day) and vigor length vigor (6.22). Seedling length, dry weight and vigor weight were the other parameters that showed the best results at 20 and 25°C. Also, germination and seedling growth indices decreased by an increase or decrease in the optimum temperature. The use of plant growth-promoting bacteria causes increased activity of ascorbate and catalase enzymes, which leads to a decrease in injuries related to non-optimum temperature and improved germination indices.
Conclusion: According to our results, to accelerate the germination rate and other parameters, it is better to inoculate seeds with bacteria strains CHA0 and 25 in the temperature range of 20-25°C.

Highlights:

The germination behaviour of safflower primed with bacteria varies at different temperatures.
Seeds inoculated with Pseudomonas fluorescens growth-promoting bacteria of CHA0 strain had better germination conditions.

Using the 20-25°C temperature improves germination indices.

Effect of humic acid on germination characteristics of Lallemantia royleana and Cyamopsis tetragonoloba under salinity stress

Bahman Fazeli-Nasab

Extended Abstract
Introduction: Lallemantia royleana is an annual herbaceous plant of Lamiaceae family in different parts of Europe, the Middle East, and especially Iran. Cyamopsis tetragonoloba L. is a plant of the legume family. A common feature between these two plants is hydrocolloid gums, which stabilize some food emulsions by absorbing water and increasing the viscosity or forming a gel in the aqueous phase. Due to its diverse and rich vegetation, Iran can produce countless types of plant gums, and many seeds such as Lallemantia royleana and Cyamopsis tetragonoloba contain valuable gums. Considering the important therapeutic and industrial applications of C. tetragonoloba and L. royleanaplants and the need for more information and reports on determining the best humic acid level and salt stress tolerance of these plants, the purpose of this research is to investigate the tolerance of two L. royleana and C. tetragonoloba plants to salinity stress in the germination stage and the initial stages of the growth of two plants under the humic acid application.
Materials and Methods: The experiment was carried out as factorial in a completely randomized design with three replications at the seed laboratory of the Faculty of Agriculture of Zabol University in 1400. In this experiment, salinity stress was investigated using sodium chloride at control (no salinity), 70, 140, 210 mM levels and humic acid at (0, 40, 80, and 120 mg/L) levels. Humic acid solution at different salinity levels was added to each petri dish containing 25 seeds.
Results: The results showed that salinity stress decreased germination percentage, radicle length, plumule length, seedling length and seedling dry weight of C. tetragonoloba. In this plant, the germination percentage decreased by 35.34% compared to the control as the salinity stress level increased to 210 mM, and with the increase of the stress to more than 140 mM, a significant decrease in the germination percentage was observed. The maximum plumule length of L. royleanaplants was obtained in 70 mM salinity treatment and 40 mg/L fertilizer level. The maximum radicle length in the L. royleanaplants plant was obtained in the treatment of 40 mg/L of humic acid at a 70 mM salinity stress level. Also, the results showed that the maximum radicle length (1.46 cm) in the C. tetragonoloba plant was related to humic acid pretreatment at 70 and 140 mM salinity and fertilizer levels of 40 and 80 mg/L.
Conclusion: In general, it can be stated that the germination indices significantly decreased under stress conditions, and this indicates that humic acid is a suitable pretreatment that can improve the growth indices of C. tetragonoloba and L. royleanaplants under stressed and non-stressed conditions. With the application of humic acid at all salinity levels except 210 mM, the germination indices in the two mentioned plants were in a favorable condition.

Highlight:
1- The salinity stress tolerance threshold was studied in Cyamopsis tetragonoloba and Lallemantia plants.
2- Humic acid fertilizer in this study mitigated the destructive effects of salinity stress in Cyamopsis tetragonoloba and Lallemantia plants.

Investigation of coleoptile and mesocotyl as the most important factors for the establishment of bread wheat seed under rain-fed conditions

Roohollah Abdolshahi

Extended Abstract
Introduction: Wheat coleoptile protects the plumule and the first leaf so they can move from the embryo to the soil surface. Coleoptile is essential for plant establishment. Cultivars with longer coleoptiles and mesocotyls are sown deeper and are more successful under drought stress conditions. However, there is not much information about their genetics. The objective of the present study was to evaluate the coleoptile and mesocotyl of Iranian, overseas and the lines developed as a part of Shahid Bahonar University breeding program, and estimate of genetic parameters of these traits.
Materials and Methods: In this research, 30 bread wheat genotypes originated from Iran, CIMMYT, ICARDA, USA, and Australia and five lines from Shahid Bahonar University of Kerman breeding programs were sown at a 10 cm depth of soil in the research field of Shahid Bahonar University in a randomized complete block design with seven replications. Each plot consisted of three rows with two meters long and a 5 cm intra-row spacing. At harvest, the plants were gently removed from the soil, and after removing the soil from the root area, the roots were washed. In this study, coleoptile and mesocotyl length, number of seminal roots, root length, root and shoot dry weight were measured.
Results: Coleoptile and mesocotyl are important traits for increasing drought tolerance in bread wheat. In the present research, mesocotyl length varied from 5.20 for Excalibur to 2.08 for Zagros, and showed a high heritability (0.48) and response to selection (11.61%). Furthermore, this trait had a positive significant correlation with coleoptile length (r=0.53**), root weight (r=0.38*) and shoot weight (r=0.36*). Seminal and nodal root number had the highest (0.59), while root length had the lowest (0.13) narrow-sense heritability. Overall, suitable cultivars for rain-fed conditions had higher coleoptile and mesocotyl than the others. Breeding lines in Shahid Bahonar University of Kerman suitable for rain-fed conditions had longer coleoptile and mesocotyl lengths. Root and shoot dry weight had a significant positive correlation (r=0.82**).
Conclusions: In general, breeding programs to increase grain yield differ under rain-fed and irrigated conditions. In wheat breeding programs under rain-fed conditions, special attention should be paid to coleoptile and mesocotyl traits. These traits were not influenced by the plant growth habit.

Highlights:

Mesocotyl of the Iranian cultivars was evaluated for the first time.
Breeding lines developed by Shahid Bahonar University of Kerman suitable for rain-fed had appropriate coleoptiles and mesocotyls.
Coleoptile and mesocotyl had a significant and positive correlation.

Evaluating the possibility of increasing freezing tolerance in chickpeas (Cicer arietinum) by seed priming

Reza Tavakol Afshari

Extended Abstract
Introduction: One of the major reasons behind the unstable yield of chickpea, is the simultaneity of the reproductive stage with drought and late-season heat. Autumn sowing of chickpea is among the suitable approaches to improve chickpea yield. On the other hand, freezing stress is a limiting factor in the autumn sowing of chickpea. Recently, seed priming has been developed as an essential method to induce plant tolerance to environmental stress. The priming will result in a rapid response of the plant to stress. Freezing, as an environmental stress, limits the growth and development of many plants in different parts of the world. Studies show that in addition to acclimation, short-term biotic and abiotic stresses as pretreatment could also increase the plant's tolerance to cold stress. This process alters the freezing response positively.
Material and Methods: This experiment was conducted as a factorial in a completely randomized design with three replicates at the greenhouse of the Research Center for Plant Sciences of Ferdowsi University, Mashhad Iran, in 2018. The experimental factors consisted of various temperatures (0, -12, -15, and -17 °C), seed priming at 10 levels (control (without priming), hydropriming, priming with sodium chloride, salicylic acid, sodium nitroprusside, phosphate solubilizing bacteria and potassium solubilizing bacteria, amino acids, potassium nitrate, and zinc sulfate) and different chickpea genotypes (MCC505, ILC8617, MCC495, and Saral cultivar). In this experiment, the measured parameters included survival percentage, electrolyte leakage percentage, and lethal temperature resulting in 50% mortality according to the electrolyte leakage and survival percentage.
Results: The results showed that the application of hydropriming, priming with sodium nitroprusside and zinc sulfate had favorable effects on the survival rate and electrolyte leakage. Among these, priming with sodium nitroprusside increased the survival percentage compared to the control (23%) at the -15 and -17 °C in the Saral cultivar, at -15 °C in the ILC8617 genotype, and at -12 and -15 °C in the MCC495 genotype treatment to 68, 58, 85 and 55 percent, respectively. In addition, this treatment reduced the electrolyte leakage by 13% at -15 °C in the ILC8617 genotype compared to the control treatment. Further, the mentioned treatment resulted in a 40% reduction in lethal temperature resulting in 50% mortality according to the survival percentage. In the MCC495 genotype compared to the control treatment.
Conclusion: Overall, the cold stress in the chickpea plants resulted in an increase in electrolyte leakage and a decrease in the survival percentage. Application of sodium nitroprusside priming by improving cold stress tolerance resulted in a reduction of lethal temperature resulting in 50% mortality based on electrolyte leakage and survival percentage results. Additionally, the applied priming in improving the cold stress tolerance mainly improved the survival percentage compared to the improvement in the electrolyte leakage.

Highlights:

The effect of different primings on the freezing tolerance of chickpeas was investigated and determined.
The freezing tolerance threshold of chickpea seedlings was determined at the laboratory under different primings.
The respondents of genotypes to priming and the behavior of genotypes towards each other were investigated.

The effects of pre-dispersal seed predation on rare and common astragalus species in the Karsanak area in Chaharmahal and Bakhtiari province

Iraj Rahimi

Extended Abstract:
Introduction: Predation is the common fate of most seeds produced by plants. Loss of seeds due to predation can be harmful to plants and causes such species to become rare, as rare species are vulnerable to extinction through processes that disrupt the mechanisms of plant dispersal. Therefore, the purpose of this study was to investigate the effects of pre-dispersal seed predation on rare astragalus species and their common counterparts.
Materials and Methods: In order to investigate the effects of pre-dispersal seed predation, 12 species including 6 species with herbaceous life form (including three rare species (A. Caraganae, A. Heterophyllus and A. Holopsilus) and three common species (A. Angustiflorus, A. Curvirostris and A. Effusus) and 6 species with shrub life form (including three rare species (A. Cephalanthus, A. Camphylanthus and A. Cemerinus) and three common species (A. Verus, A. Susianus and A. Rhodosemius) were compared in 2018 and 2019. From each plant type, 20 and from each plant type 10 pods (for each plant type 200 pods), randomly selected and the parameters of area size, perimeter length, length, width, length-to-width ratio, circularity, and distance between IS and CG from the seed center were measured and compared for both pods and seeds of these species. Also, pod mass and seed mass, number of pods and seeds attacked by predators, number of healthy seeds, pod shape and seed shape of species were compared.
Results: The results of comparing the mean morphological characteristics of seeds between herbaceous and shrub astragalus species showed the highest and lowest area size, perimeter length, length, width, length-to-width ratio, circularity, and distance between IS and CG from the seed center, was related to common astragalus species. in the case of shrub species, most of the characteristics were related to common astragalus species, and the lowest characteristics were related to rare astragalus species. The results of morphological characteristics of pods between herbaceous and shrub species showed that the highest and lowest characteristics belonged to both groups of common and rare species. The results showed that the highest and lowest means of seed mass, number of damaged seeds, number of healthy seeds, and seed shape under the influence of pre-dispersal seed predation among herbaceous species showed that the highest and lowest means of seed mass, number of damaged seeds, belonged to common species. the highest and lowest numbers of healthy seeds and seed shapes belonged to rare species. Among the shrub astragalus species, the highest seed mass, the number of damaged seeds, the number of healthy seeds, and the seed shape were related to common astragalus species, and the lowest of these characteristics were related to rare astragalus species.
Conclusion: The overall results showed that the more species that can produce seeds of larger and smaller sizes, the better the distribution status. And the larger the seed and pod mass of the plant and the larger the shape, the more predators attack those species, but the amount of predator attacks does not lead to the rarity of the species.

Highlights:

The role of pre-dispersal seed predation on rare and common astragalus species was investigated.
Morphological characteristics of seeds and life forms of rare and common astragalus species were compared.

Effect of pretreatment with seaweed extract (Ascophyllum nodosum) on germination traits and heterotrophic growth of soybean (Glycine max) seeds under aging conditions

Mehdi Baradaran Firouzabadi

Extended Abstract
Introduction: Seed aging is a phenomenon that occurs during the life of any seed. Changes that occur during aging affect seed quality. Through the process of aging, seed vigor is the first trait of the seed quality that decreases, followed by a decrease in germination capacity, seedling growth and establishment. Hence, one way to stimulate germination and increase the establishment of seedlings from aging seeds is seed pre-treatment using different materials such as brown seaweed extract. The aim of this study was to investigate the effect of seaweed extract pretreatment on germination traits and heterotrophic growth of un-aged and aged soybean seeds.
Materials and Methods: The experiment was designed and implemented at a laboratory in the faculty of agriculture of Shahrood University of Technology in 2019. Treatments included seed aging at two levels (un-aged seeds and aged seeds) and pretreatment with seaweed extract at seven levels (zero, distilled water, 0.1, 0.2, 0.3, 0.4 and 0.5 %). The experiment was carried out as a factorial in a completely randomized design (CRD) with three replications in the germinator environment. The seeds were aged by being placed at 41°C and 95% relative humidity for 72 hours. Seed pretreatment seaweed extract was done for 6 hours in accordance with the principles of seed aeration.
Results: Aging reduced germination percentage and germination rate, allometric growth ratio, seedling length vigor index, seed reserves use efficiency and seed vigor index. Malondialdehyde content and electrical conductivity of aged seeds were 37.68% and 38.32% higher than un-aged seeds respectively. Seed pretreatment with 0.1, 0.2 and 0.3% of seaweed extract significantly increased germination rate, germination index and seed reserves use efficiency. Slicing interactions of aging and seaweed extract showed that seed pretreatment with 0.1, 0.2 and 0.3% of seaweed extract significantly increased germination rate and germination index in un-age seeds. Pretreatment of aged seeds with 0.1, 0.2 and 0.3% seaweed extract increased germination percentage by 8.73%, 8% and 15% compared to the control (aged seeds without pretreatment), respectively. The use of distilled water and all levels of seaweed extract in this study increased the seed vigor index and decreased the electrical conductivity. The amount of malondialdehyde in aged seeds was reduced by using all levels of seaweed extract. The use of 0.2, 0.3, 0.4 and 0.5% of the extract increased the amount of seed reserves use rate and fraction of seed reserves mobilization in aged seeds.
Conclusions: Finally, in the scope of this research between the concentrations used, the concentration of 0.3% seaweed extract was better than the others. It can also be suggested that the use of seaweed extract as a seed pretreatment improves the effects of seed aging on soybeans.

Highlights:
1-The effect of pretreatment with seaweed extract with concentrations of 0.1 to 0.5% on un-aged and aged soybean seeds was investigated for the first time.
2-Using a concentration of 0.3% seaweed extract for the pretreatment of soybean seeds was introduced as the best concentration.
3- Seaweed extract was introduced as an important antioxidant to improve physiological traits in soybean seeds.

Effect of nutrient and soil moisture of maternal environment on quality and biochemical characteristics of Dragon’s head (Lallemantia iberica) seed

Arezoo Paravar

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.

Highlights:

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

Effect of chitosan on germination indices of common bean (Phaseolus vulgaris) (cv. Sedri) seeds under salt stress

Mohammad Sedghi

Introduction: Today, population growth has placed a significant burden on global agricultural resources. As a result, meeting global food demand and increasing farmers' incomes has become a challenging task. Salinity is one of the most harmful factors in the arid and semi-arid regions of the world that influences crop production. Seed priming is a technology by which seeds are physiologically and biochemically prepared for germination before being placed in their bed and exposed to the ecological conditions of the environment. The aim of this study was to evaluate the efficiency of the effect of chitosan on bean germination indices under salt stress.
Materials and Methods: The experiment was conducted as factorial based on a completely randomized design with four replications in a row (tube or sandwich culture) between filter paper at the University of Mohaghegh Ardabili in 2021. Treatments included four salinity levels (0, 50, 100, and 150 Mm) and four chitosan levels (0, 25, 50, and 75% by weight volume), all of which had been dissolved in 1% acetic acid. The studied traits included germination coefficient, allometric coefficient, daily germination rate, mean daily germination, seedling length and weight index, radicle length, plumule length, seedling length, radicle fresh and dry weight, plumule fresh and dry weight and residual dry weight. Data analysis was performed using the SAS 9.2 software and Duncan's test at p<0.05 probability level was used for mean comparison.
Results: The results showed that salinity stress decreased allometric coefficient (AC), seedling length vigor index (SLVI), radicle and seedling length (RL and SL), and radicle fresh and dry weight (RFW and RDW) and increased daily germination rate (DGS) and residual dry weight (RDW). Seed pretreatment with chitosan increased AC, SLVI, RL, SL, RFW, and RDW. The comparison of the means showed that there was a significant difference between the levels of chitosan so that the highest number of traits was obtained from the use of 75% chitosan and the lowest was obtained from the chitosan-free treatment. SLVI, SL, and RDW in 75% chitosan pre-treatment were higher at about 31, 26, and 27% compared to the control (priming with distilled water), respectively. The highest AC was observed in priming with 50% chitosan. Comparison of the mean for salinity stress also showed that the highest and lowest values of the measured traits respectively were obtained from the application of 0 and 150 Mm salinity levels. Also, with increasing salinity, chitosan increased germination coefficient (GC), seedling weight vigor index (SWVI), plumule length (PL), and plumule fresh and dry weight (PFW and PDW).
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with 75 % Chitosan may be considered an effective way to improve seed germination of bean. It also can reduce the harmful effects of salinity stress on some traits in bean seedlings and improve seedling growth. Also, pretreatment with distilled water is an easy, low-cost and effective way to increase bean seedling germination and growth indices. Farmers can use this method for fast germination and better seedling growth under salt stress conditions.

Highlights:

The effect of different concentrations of chitosan on the germination of bean seeds was investigated.
Priming with chitosan increased the allometric coefficient, seedling length vigor index, radicle and seedling length, and radicle fresh and dry weight.
A suitable method for reducing the harmful effects of salinity and increasing germination indicators of beans was introduced.

Effect of salicylic acid on germination and early growth of Securigera securidaca seedling under salinity stress

Vahid Mohasseli

Extended Abstract
Introduction: Lentil is a dicot, annual, and cross-pollinating plant that is found mainly in Fars, Khuzestan and East Azerbaijan provinces. The seeds of the plant are used in the treatment of cholesterol and blood sugar. Abiotic stresses such as salinity are important factors in reducing plant growth and yield. Although salinity can remarkably affect plant growth, its intensity depends on duration, type, plant species and growth stage. The greatest effect of salinity during the germination process is on germination rate and percentage and radicle and plumule length, as the increased concentration of ions in Therefore, studying of plant germination under salt stress and application of compounds such as salicylic acid to improve plant tolerance to salinity in saline areas can serve as a guideline for the cultivation of plants under such conditions. Therefore, this research aimed to study the effect of salicylic acid on the germination and growth parameters of Securigera securidaca L. under salinity conditions.
Materials and Methods: The experiment was conducted as a factorial in a completely randomized design with three replications under the germinator conditions in the laboratory of Fars Agricultural and Natural Resources Research and Education Center. Experimental treatments consisted of 5 levels of salinity stress (0, -0.3, -0.6, -0.9 and -1.2 MPa) and 3 levels of salicylic acid (0, 1 and 2 mM). The seeds were soaked in the treatments for 24h. At the end of the experiment (8 days), germination percentage and rate, seed vigor index, and fresh and dry weight of radicle and plumule were measured and calculated.
Results: The results showed that all plant responses were affected by different osmotic potentials at p<0.01 compared with the control. The highest germination percentage was 91.11 under stress-free conditions and the application of salicylic acid at 1 mM. During the comparison of means for salicylic acid, the highest mean plumule length (10.88 mm) was related to 1 mM salicylic acid solution and the lowest (6.35 mm) was for control treatment, which showed an increase of 71.34%. Also, soaking seeds with salicylic acid caused an 84.98% increase in root fresh weight. An increase in salinity led to 96.30 and 94.62% decrease in radicle and plumule dry weights, respectively.
Conclusions: The study showed that soaking seeds with salicylic acid improved germination under salt stress conditions. Therefore, seed placement in salicylic acid solution (1 Mm) prior to cultivation can be used to improve the germination of Securigera securidaca L. under salinity conditions.

Highlights:
1- The most suitable concentration of salicylic acid for seeds soaking to increase plant tolerance to salinity stress is 1 mM.
2- Soaking of Securigera securidaca L. seeds in salicylic acid increases germination, seed vigor index and radicle and plumule length and weight under saline and non-saline conditions.

Germination response of Dracocephalum kotschyi to sulfuric acid pretreatment, gibberellic acid, and mycorrhiza at different temperatures

Gholamrez Khajoei-Nejad

Extended Abstract
Introduction: The application of different physical, chemical, and hormonal treatments mainly improves the germination of plants such as Dracocephalum kotschyi Boiss that have a seed dormancy mechanism. However, the interaction effects of germination, temperature, pretreatment with sulfuric acid, treatment with gibberellic acid and mycorrhiza on D. kotschyi germination have not been studied. Therefore, this experiment was performed in vitro to study the effect of seed pretreatment on improvement of germination characteristics of D. kotschyi seed.
Materials and Methods: The treatments studied in this experiment included (1) pretreatment of seed coat with sulfuric acid (97-95 %, for 10 min) and non-pretreatment (distilled water); (2) different treatments including treatments with concentrations of 0, 250, and 500 mg L^-1 gibberellic acid (GA) or inoculation with mycorrhiza suspension in two separate experiments; and (3) two temperature treatments; room and refrigerator (about 4 °C) temperatures. The experiment was performed as a factorial based on a completely randomized design with four replications and different germination and initial seedling growth indices were examined.
Results: Gibberellic acid application at room temperature resulted in a significant increase in germination percentage and rate, whereas there was no significant difference between different levels of gibberellic acid and control at 4 °C. Similarly, the application of 250 mg L^-1 GA improved seedling length and seedling vigor index at room temperature. While pretreatment with sulfuric acid significantly reduced germination and seedling growth indices compared to non-pretreatment, inoculation with mycorrhiza suspension in both pretreatment conditions compensated the germination reduction caused by sulfuric acid pretreatment by improving germination. Similarly, while the highest seedling length and vigor were obtained from mycorrhizal treatment at room temperature in non-pretreatment with sulfuric acid, at 4 ° C, inoculation with mycorrhiza also significantly reduced the loss in seedling length and seedling vigor index caused by sulfuric acid application.
Conclusion: According to the findings, it seems that the application of 250 mg L^-1 GA at room temperature can be considered to improve the germination trend of D. kotschyi. Also, according to the results, treatment with mycorrhiza in sulfuric acid-free treatment at room temperature can be recommended as optimal conditions to improve the germination of D. kotschyi.

Highlights:
1- The interaction effect of chemical pretreatment with biological and hormonal treatments on the germination of Dracocephalum kotschyi was investigated.
2- The application of gibberellic acid at room temperature improved germination compared to the control, whereas it had no effect on germination at 4 °C.
3- Application of mycorrhiza reduced germination loss caused by pretreatment with sulfuric acid and led to maximum germination and seedling growth.