جستجوی مقالات مرتبط با کلیدواژه « priming » در نشریات گروه « زراعت »

The researchers have been forcing to investigate and find an edible alternative high forage quality plant that has a well-tolerated instinct against adverse environmental conditions. Alhagi, a genus of Fabaceae is one of the most important halophyte plants in the world, as an industrial forage product used in the near future, medicinal production and pharmaceutical use. There are many reasonable that Alhagi plants productivity and satisfactory yield requires good seed germination and seedling establishment. Generally, germination and seedling establishment is the most decisive stage of Alhagi plants life cycle to environmental stress. Moderate to severe salinity stress is main abiotic causes of Alhagi plants productivity loss at the seedling growth stage. High accumulation of Na+ and Cl- ions cause various negative influences that impact Alhagi production, such as delays in the response of the plant to environmental conditions, retardation of germination, growth and development, inhibition of enzymatic activities and accumulation of some compatible osmolyte. In addition, to the salinity stress, the seed germination, seedling establishment and total dry matter production in Alhagi plants occurs depends on a seed priming and type of species. However, few research studies have so far investigated the impact of different seed priming on the total dry matter production as well as some physiological responses in Alhagi species.

Two separate experiments was conducted to investigate seed priming (non-priming, hydro priming, hormonal priming with 50 ppm gibberellin and hydro priming + hormonal priming with 50 ppm gibberellin) and different salinity levels (urban water source with EC=0.96 dS.m-1, 8 and 16 dS.m-1 using seawater Persian Gulf) on seed germination, dry matter and some physiological response of Alhagi species (Alhagi maurorum Esfahan ecotype and A. graecorum Khuzestan ecotype). The first experiment (seed germination) was carried on in the petri dish culture and second experiment (in the pot) at the field conditions was performed under split factorial experiments were conducted based on a randomized complete block design with four replications in Department of Plant Production and Genetics, Faculty of Agriculture, Shahid Chamran University (Ahwaz, Iran) during 2020-21. Meanwhile, during research, after calculating of the leaching fraction, EC of the root environment was controlled three times with an interval of one month by preparing a saturated extract from the pot bed and only in the third sampling was performed a leaching in the treatments of 16 dS m-1, with a salinity level lower than the studied treatment (8 ds.m-1).

The results showed a significant effect of salinity × priming × species interaction on all studied traits except for transpiration rate, Na and K content. In the case of transpiration rate, only the effects of salinity and priming were significant. Mean comparison results showed that the highest amount of seed germination, total dry matter, net photosynthesis rate, sub-stomata CO2 concentration, photosynthetic water use efficiency and number of leaves per plant in A. graecorum Khuzestan ecotype under Non-salinity stress and Hydro priming + Hormonal priming with 50 ppm gibberellin treatment (increased by 29.1, 1.52, 26.8, 98.7, 15.6 and 38.8 percent respectively compared to the Non-priming and Non-salinity stress treatment in the A. maurorum Esfahan ecotype). The highest level of mesophilic conductance was observed in A. graecorum Khuzestan ecotype under Non-priming and 8 dS.m-1 salinity stress treatment (with an average of 0.492 mmol CO2.m-2.s-1).

In this experiment, results showed significant differences in total dry weight, net photosynthesis rate, transpiration rate, sub-stomata CO2 concentration, mesophyll conductance and photosynthetic water use efficiency between two Alhagi species at different salinity conditions using Persian Gulf water. Indeed, dry matter and photosynthesis traits in both Alhagi species responded negatively to increasing salinity levels and increasing of salinity up to, 8 dS m-1 induce the loss in physiological responses. Among the priming treatments, the hydro priming + hormonal priming with 50 ppm gibberellin showed a more favorable condition in the two Alhagi species in terms of the studied traits. Finally, in cultivation and development of Alhagi species for breeding programs in saline coastal lands and for the restoration of pastures, according to the results, A. graecorum Khuzestan ecotype under the combined treatment as hydro priming + hormonal priming with 50 ppm gibberellin, recommended for high production.

In order to investigate the effect of different concentrations of KNO3 on physiological and biochemical properties of maize (Zea mays L.) under salinity stress a factorial experiment was conducted based on completely randomized design at the University of Mohaghegh Ardabili in 2021. Treatments included three salinity levels (0, 100 and 200 Mm) and three KNO3 levels (0, 1.5 and 3%). The results showed that the highest germination percentage (GP), germination rate (GR), germination uniformity (GU), radicle and plumule length (RL and PL) and radicle fresh and dry weight (RFW and RDW) was related to priming with KNO3 3% and without salinity. Mean of germination time (MGT) compared to the control showed a reduction about 53%. The activity of catalase, peroxidase and superoxide dismutase enzymes in priming with KNO3 3% and 200 mM salinity compared to the control showed an increase about 56, 68 and 67%, respectively. Salinity decreased the activity of amylase, but priming with KNO3 increased the activity of this enzyme. The total seed protein content in KNO3 3% pretreatment and without salinity was increased about 63%. In general, priming with KNO3 3% solution can be considered as the best treatment to improve the physiological and biochemical properties of corn under salinity stress.

Wheat, as a crucial staple food, has gained heightened importance following the Russia-Ukraine conflict and the escalating impacts of climate change. Its adaptability to various climates, ease of cultivation, and rich nutritional value make it indispensable. Iran, with its arid climate and saline arable lands, necessitates a focused study on innovative approaches for wheat cultivation. In this challenging environment, it's imperative to seek cost-effective methods to boost wheat production. Addressing salinity involves diverse techniques like leaching saline soils, improved irrigation management, cultivating salt-tolerant varieties, and utilizing biological fertilizers. Additionally, the application of effective microorganisms stands out as a promising biological method. By influencing the rhizosphere and leaf through biological and molecular priming, these microorganisms enhance the plant's resistance to salinity and drought, ultimately leading to increased growth and yield. Embracing such approaches is essential for sustainable wheat cultivation in these harsh conditions.

Soybean is among the most important oil crops of the world. Currently, 55% of the world's oil is supplied by soybean. Seed aging, an undesirable feature of agriculture, is one of the main problems in agriculture that leads to economic losses. Although aging is an irreversible process, its speed is delayed by proper storage and optimal storage methods. While kept under inappropriate conditions after harvesting, its quality during storage declines. Priming has a direct and indirect effect on the growth and development of plants, and its indirect effects are more beneficial than its direct effects. Priming improves the longevity of low-vigor seeds. During the priming of these seeds, a long time can occur to repair metabolic damage before any progress in germination, which ultimately prevents further deterioration. Several studies have shown that seed treatment with sodium nitroprusside during reaction with reactive oxygen species and increased activity of antioxidant enzymes is essential to protecting plants against stress. The aim of this study was to the investigate the effect of sodium nitroprusside levels on germination indices and antioxidant enzyme activity in soybean seedlings under accelerated aging test.

This experiment was conducted in 2023 as a factorial in the form of a completely randomized design with 3 replications at the University of Mohaghegh Ardabili. Experimental treatments included accelerated aging treatment at three levels (0, 24, and 48 hours) and three levels of sodium nitroprusside (0, 100, and 200 ppm).

The results showed that aging reduced germination indices including germination percentage (GP), germination value (GV), and mean daily germination (MDG). Also, priming with different levels of sodium nitroprusside, especially the 200 ppm level, improved these traits, but priming with sodium nitroprusside decreased the mean germination rate (MGR) and the mean germination time (MGT). The superoxide dismutase and ascorbate peroxidase enzyme activity due to priming with sodium nitroprusside 200 ppm compared to the control showed an increase of 22 and 26%, respectively. Also, the content of peroxidase enzyme activity showed an increase of about 34% compared to the control in priming with sodium nitroprusside 200 ppm and 48 hours aging compared to the control. The lowest catalase enzyme (7.7 units mg protein-1 min-1) was in pretreatment with sodium nitroprusside 100 ppm and without aging.

The results of this study show that among the different treatments, pre-treatment of seeds with sodium nitroprusside 200 ppm may be considered an effective way to improve germination indices and antioxidant enzymes activity of soybean and can be used as a treatment to deal with salinity conditions in soybean seedlings and improve their growth.

At present, the drastic increase in population has created an additional burden on the world's agricultural resources. As a result, meeting global food demand and increasing farmers' incomes has become a challenging task. Salinity is one of the abiotic stresses that strongly affect the germination, growth, and yield of crops. Seed priming is a simple technology that hydrates seeds to the point where the metabolic activity for germination is initiated without radicle emergence. In fact, the seeds are physiologically and biochemically prepared to germinate before being placed in their bed and exposed to environmental conditions. This research was conducted to investigate the effect of seed priming with chitosan on germination indices and biochemical traits of beans under salt stress.

This experiment was conducted at the University of Mohaghegh Ardabili in 2021 as a factorial in the form of a completely randomized design with four repetitions. The treatments included four levels of salinity (0, 50, 100, and 150 mM) and four levels of chitosan (0, 0.25, 0.50, and 0.75% w/v), all of which were dissolved in 1% acetic acid.

The results showed that salinity stress decreased germination percentage (GP), peak value (PV), and germination value (GV). However, seed priming with different levels of chitosan, especially 0.75% chitosan, improved GP, PV, and GV by 7, 21, and 17%, respectively, compared to the control. Proline content and polyphenol oxidase enzyme activity went up with increasing salinity. However, the application of chitosan 0.75% increased these traits by 34% and 43%, respectively, compared to the control (priming with distilled water). Electrolyte leakage in priming with 0.75% chitosan decreased by 31% compared to the control, which indicates the maintenance of the cell membrane stability. The content of soluble sugars in the treatment with 0.75% chitosan and 150 mM salinity showed an increase of about 78% compared to the control. The highest correlation among traits was observed between peak value and germination coefficient (r2=0.99) and between proline and polyphenol oxidase enzyme (r2=0.92).

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 germination indices and biochemical characteristics of beans and it can be used as a treatment to deal with salinity conditions in bean seedlings and improve their seedling growth.

In order to investigate Effect of different concentrations of urea on physiological and biochemical properties of maize (Zea mays L.) under Salinity Stress a factorial experiment was conducted based on completely randomized design at the University of Mohaghegh Ardabili in 2021. The investigated factors were different levels of salinity (zero, 100 and 200 mM) and different levels of urea solution (zero, 1.5 and 3%). The results showed that salinity stress decreased Germination Percentage (GP), Germination Rate (GR), Germination uniformity (GU), Radicle and Pedicel Length (RL and PL) and Radicle Fresh and Dry Weight (RFW and RDW), But priming with urea improved these traits. The highest Medium Germination Time (MGT) was related at 200 mM salinity and control (distilled water). The activity of catalase and peroxidase enzymes increased with salinity intensification and the highest amount was observed at 200 mM salinity. Priming with 3% urea solution improved these enzymes. The superoxide dismutase enzyme activity in priming with 3% urea and 200 mM salinity compared to the control showed an increase about 61%. Amylase and protein in pretreatment with urea 3% and without salinity compared to the control showed an increase respectively about 73% and 70%. According to the observed results, seeds primed with 3% urea solution had the greatest effect on salinity stress in maize. According to the observed results, seeds primed with 3% urea solution had the greatest effect on salinity stress in maize.

In order to investigate the effect of ellagic acid on the growth indices and leaf aging process in soybean, an experiment was conducted during the two years of 2018 and 2019 in the research farm of Shahrood University of Technology's Faculty of Agriculture. The experiment was carried out factorial in the form of a randomized complete block design in three replications. The experimental treatments include the initial seed quality at two levels (normal seeds and aged seeds) and the application of ellagic acid at four levels (control, priming, foliar spraying and combined application of priming and foliar spraying with a concentration of 50 mg/L). The results showed that accelerated aging decreased the amount of chlorophyll, carotenoid, plant height, leaf and stem dry weight, oil percentage and seed yield compared to the control. The use of ellagic acid in the form of priming, foliar spraying and their combination in this study increased the percentage of oil by 0.23, 0.24 and 0.29%, respectively, compared to the control. Priming, foliar spraying and the combined application of priming and foliar spraying with ellagic acid improved the grain yield by 23.59, 23.23 and 55.48%, respectively. The use of ellagic acid as seed priming and foliar spraying better than other levels. Finally, it is recommended to use this material as a priming to increase the percentage of oil and yield of soybean.

In order to investigate the effect of gibberellic, ascorbic, salicylic acid pretreatments on the germination of Lolium prenne L., Lolium rigidum Gaudin species. An experiment was designed in the laboratory of the Caspian Forest Seed Center. This research was conducted with the treatment of gibberellic acid with concentrations of 125, 250 parts per million for 24 hours and ascorbic acid with concentrations of 100, 200, 300 mg/liter and salicylic acid with concentrations of 200, 300, 400 mg/liter for a period of 24 hours. The time was 12 hours in the form of a completely random design with 3 repetitions. In addition, distilled water was considered as control treatment. In this experiment, traits such as germination percentage, germination speed, germination value and seed germination index were evaluated. The results of analysis of variance and mean comparison showed that there is a significant difference between the treatments in terms of germination percentage, germination speed, germination value and germination index at the level of 1% and priming increases the germination percentage and germination speed. , germination value and germination index. As a result, gibberellic, ascorbic, and salicylic acid treatments as suitable pretreatments significantly increased the seeds of Lolium rigidum Gaudin species. and Lolium prenne L. are in the germination stage, and ascorbic acid treatment at a concentration of 300 mg/liter caused better germination compared to other treatments.

The use of seed priming methods has been introduced today as one of the factors to increase the germination and establishment of seedlings and plant under adverse environmental conditions, especially salinity. Therefore, in this study, the effect of seed priming with gibberellic on germination and consumption of triticale seed storage materials under salt stress conditions was investigated. The experimental treatments in this study were 5 levels of salinity stress (zero, 40, 80, 120 and 160 mM) and 4 levels of seed priming (zero, 25 and 50 ppm gibberellic acid and control seed without prime) with 3 replications. The results showed that the highest percentage of germination (95.33%), germination index (41.65 seeds per day), seedling length (19.27 cm) and the percentage of normal seedling (95.33%) was related to seed priming with gibberellic acid 50 ppm. Also, the highest seed vigor index (1836) was related to seed pretreatment with 50 ppm gibberellic acid. In all the applied salinity levels, the highest weight of mobilized seed reserve was obtained from seed priming with 50 ppm gibberellic acid. The highest seed reserve utilization efficiency from control seeds at 160 mM potential and the highest seedling dry weight and seed reserve depletion percentage in nonstressed conditions were obtained from seed priming with 25 and 50 ppm gibberellic acid. Seed germination improves triticale germination components under salinity stress conditions and increases the plant's tolerance to salinity against salinity stress in the germination stage.

The uniformity and emergence percentage of seeds have an importance role on the yield and quality of crops in the field. The aim of this research was to evaluate the seeds emergence and seedlings of three populations of the lanceleaf thyme species (Thymus lancifolius Celak) by Priming methods. In order to evaluating seed emergence and seedling vigor of three populations of (Thymus lancifolius Celak), a factorial experiment based on completely randomized design with three replications was conducted in Research Institute of Forests and rangelands, Tehran, Iran in 2015-2016. The factors A was including: three populations of (Thymus lancifolius Celak) and factor B were seven treatments as follows: osmopriming (PEG 0.3 and 0.6Mpa), hormonal priming (250 and 500 ppm of Gibberellic acid), Matrix priming (Vermicolit 1%) hydropriming (distilled water) and control. The emergence characteristics including of seed emergence percentage and speed of emergence, root and shoot length, vigor index, seedling fresh and dry weight were measured. The mean comparison three populations showed that all emergence traits of population 13490-Arak were more than the other two populations. The maximum emergence percentage as (81.19) obtained using vermiculite treatment. using vermiculite, seedling Fresh weight, (578.8), dry Weight, (47.78), dry matter percentage (7.82%) were more than other treatments. High speed of emergence observed as (5.82 seeds per day) with effect of Gibberellic acid 250 ppm. Regarding to result of this research work, it was proved that two Priming technique as Matrix priming (Vermiculite) and Hormonal priming (Gibberellic acid) were effective method compare with other method. Therefore these two methods are recommending for domestication and optimum establishment of medicinal plant of (Thymus lancifolius Celak).

Due to the fineness of parsley seeds, several problems may arise, such as the impossibility of using planting machines and the displacement of seeds by water, reduced germination and growth due to increased planting depth or lack of seed establishment in the soil, and consequently, increased seeding rate. Therefore, it is necessary to use methods to increase germination ability and improve the establishment of parsley seeds and seedlings in the soil. This experiment aimed to determine the most effective biopriming and gibberellin treatments for better germination and establishment of parsley seeds.

In order to determine the best biopriming and gibberellin priming treatments on germination characteristics and establishment of parsley seed, three experiments with four replications were conducted in the seed science and technology laboratory of Yasouj University in 2015 and 2016. The first biopriming experiment was carried out using growth-stimulating bacteria in a completely randomized design with eight treatments including bacterial isolates Pseudomonas fluorescens strain 21, Bacillus biosobetyl strain, Enterobactercus cloac strain 5, also two and three compounds of these bacteria along with control treatment. The second experiment was carried out with five treatments of Trichoderma harziarum (T36, T39, T42, and T43) isolates with control treatment. Finally, the third experiment was performed as a factorial in a completely randomized design with concentrations of gibberellin hormone (0, 50, 100, and 200 ppm) and prime times (6 and 12 hours). The measured traits were seedling length, seedling dry weight, germination percentage, and seedling length vigor index.

The results showed that the best treatments for the first experiment were biopriming with Enterobacter + pseudomonas, for the second experiment biopriming with T36 fungus strain, and for the third experiment 50 ppm of gibberellin prime for 6 and 12 hours. The results showed that the majority of biopriming and hormone prime treatments improved the quality of parsley seeds so that the germination percentage in control seeds was 70%. This value increased by 31% compared to control treatment following priming with growth-stimulating bacteria (Pseudomonas+ Enterobacter), which showed the highest rate among all treatments applied in this study. The use of 50 ppm of gibberellin priming for 6 and 12 hours increased germination by 19% and 14% compared to the control treatment, respectively.

The results of this study showed that biopriming with Pseudomonas + enterobacter had the greatest effect on improving the quality and germination characteristics of parsley seed. In general, biopriming except for T42 fungi, and also gibberellin priming showed improvement in the quality and germination properties of parsley seed.

Highlights:

1. The effects of using biopriming and hormone prime are common, while it is not clear for parsley.
2. Biopriming with Pseudomonas+ enterobacter had the greatest effect on improving the quality and germination characteristics of parsley seeds.
3. Priming with T42 fungus reduced the quality and germination characteristics of parsley seeds.

Germination and seedling establishment are critical and important stages in the life cycle of plants. Therefore, the study of germination and methods of breaking on seed dormancy in plants is of great importance. One of the corrective operations on improving the seed yield of rangeland plants is seed priming. Priming is an operation on the seed that causes the seed to absorb a sufficient amount of water to accelerate the germination process. Trifolium resupinatum is a clover. In this study, in order to germinate seeds from treatments of 100, 200 and 300 mM sodium chloride in 24, 48 and 72 hours, gibberellic acid 125 and 250 ppm during 12, 24 and 48 hours and 0.01 solution, 0.02 and 0.03% of potassium nitrate were used for 12 and 24 hours, respectively. Distilled water was also considered as a control treatment. The study was conducted in a randomized statistical design with 3 replications and two-way analysis of variance was used to analyze the data. Traits such as germination percentage, germination rate, germination index, shoot length, root length, number of germinated seeds, seedling length and seed vigor index were evaluated. The results showed that in the seed germination of Iranian clover species, three chemical treatments had better results in terms of yield of the germination process of the species than other treatments and were recommended as the most desirable pretreatments and potassium nitrate and then acid treatments. Gibberellins had the greatest effect on the seed Dormancy breaking.

In addition to plant growth enhancing bacteria, the effect of gibberellic acid on increasing the ability of germination and seedling vigor index has been investigated and confirmed. To determine the best treatments for coating along with Enterobacter cloacae+Pseudomonas fluorescens and gibberellic acid on germination characteristics and establishment of parsley seed, three experiments were conducted in the seed laboratory of Yasouj University in 2015 and 2016. The first experiment was conducted based on a CRD design on non-primed seeds to select the most suitable coating materials for covering parsley seeds with 4 pelleting treatments including control, vermiculite (V), perlite (P) and kaolin (K). To determine the most suitable combination of coating material, biopriming and hormone priming for seed coating, the second experiment was conducted in a factorial experiment based on a completely randomized design with 12 treatments and 4 replications. The treatments of the second experiment were also used in the third experiment in the greenhouse condition. The best treatments for the first experiments were P20K10 (perlite with a weight ratio of 20 and kaolin 10), P20K20V5 (perlite with a weight ratio of 20, kaolin 20 and vermiculite 5) and P30K10 and in the second experiment were P20K10-GA3-50ppm-6h and also P20K20V5-GA3-50ppm-12h. Finally, in the greenhouse experiment, the use of P20K10-GA3-50ppm-6h treatment was determined as the best treatment to increase the percentage of final field emergence and field emergence rate. The results of this study showed that the use of P20K10-GA3-50ppm-6, other than increasing the volume and physical characteristics, can be useful as a strategy to improve the quality of germination and seedling of parsley.

Ellagic acid is a natural polyphenol compound that has strong antioxidant properties and reduces the effects of various stresses in plants. In order to investigate the effect of ellagic acid on protein percentage and soybean yield, an experiment was conducted in the two crop years of 2018 and 2019 in the research farm of Shahrood University of Technology. Treatments include accelerated aging on two levels of normal seed and aged seed and the application of ellagic acid on four levels (control, seed pre-treatment, foliar spraying and the combination of seed pre-treatment and foliar spraying with ellagic acid with a concentration of 50 mg/L) in the form of a factorial experiment with a basic design of randomized complete blocks in three replications. The number of pods per plant, the number of seeds per pod and the 100 seed weight per plant obtained from aged seeds decreased by 11.64, 4.16, and 13.13%, respectively, compared to the control. The combined use of seed pretreatment and foliar spraying of ellagic acid in normal and aging conditions caused a significant increase of 10.00 and 11.30% in the number of seeds in the pod compared to the non-application of this substance in these conditions. The combined use of seed pretreatment and foliar spraying of ellagic acid caused an increase of 20.89 and 51.93% in the weight of 100 seed and seed yield, respectively, compared to the control. The application of ellagic acid in normal conditions did not show any effect on the protein percentage, while the use of this substance in aging conditions by the form of seed pretreatment, foliar spraying and the combined use of seed pretreatment and foliar spraying, led to an increase of 0.88, 0.40, and 0.86 percent of protein, respectively. It is possible to suggest the combined use of pretreatment and foliar spraying with ellagic acid to increase seed yield and protein percentage in plants obtained from normal and aged soybean seeds.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

Soybean seeds are sensitive to storage due to their high oil content and they aged quickly. Aging of seeds leads to a decrease in the percentage and speed of germination and ultimately to a decrease in seed yield. Although the aging rate can be reduced with proper storage methods, the application of some treatments on the aged seeds or spraying some substances on the plants obtained from these seeds can be effective in improving the seed yield. The use of anti-aging substances such as seaweed extract in plants can act as antioxidants and reduce the effects of aging.
 
In order to evaluate the phenological stages and yield of soybean, an experiment was carried out in the research farm of Shahrood University of Technology during 2019 and 2020 in three replications. The treatments include the initial seed quality in two levels (normal seeds and aged seeds) and seaweed extract (Ascophyllum nodosum) in four levels (control, priming, foliar spraying and combined application of priming and foliar spraying with a concentration of 0.3%). The experiment was carried out as a factorial in the form of a basic design of randomized complete blocks.
In this research, applying accelerated aging caused a significant increase in phenological traits in soybean plants. The use of seaweed extract as a priming and the combined use of priming and foliar spraying could increase the rate of occurrence of phenological traits to a significant level. The seed yield in plants obtained from aged seeds was 32.69% less than that of control plants. The use of seaweed extract as priming, foliar spraying and the combined use of priming and foliar spraying increase the seed yield by 43.54, 15.69 and 87.85 percent, respectively. Aging caused a significant decrease of 23.50 and 25.33 percent of final emergence percentage. Pretreatment of normal and aged seeds with seaweed extract in the first year increased this trait by 16.33 and 7.33% compared to the absence of seaweed extract. In the second year of the experiment, the application of seaweed extract resulted in a 12.67% increase in seedling growth under normal conditions, and an 8.33% increase was recorded with the application of seaweed extract under aging conditions.
 
In this study, the application of seaweed extract as seed priming better than foliar spraying. It is possible to recommend priming and the combination of priming and foliar spraying with seaweed extract to accelerate the occurrence of phenological traits in soybeans. The combined use of priming and foliar spraying of seaweed extract is recommended to improve the performance of soybeans in normal and aged conditions.

Canola is one of the most important oilseeds that plays a major role in providing human edible oil and in this regard, it is in the third place after soybean and palm oil. There are many strategies to improve growth, yield and precocity in plant species including rapeseed. Seed priming is a pre-planting strategy that is very effective in improving germination, grow rate, seedling establishment and early maturity. As a result, considering the importance of increasing the quantity and quality of rapeseed and the positive effects that treatment has on improving germination, increasing yield and early maturity in rapeseed, In this study, investigating the effect of seed priming by gibberellin and salicylic acid on the characteristics of germination, growth and seed yield of canola was done.

In this research, a factorial experiment was conducted in a randomized block design with three factors. The first factor of genotype (Lord and Hayola 308), the second factor of salicylic acid (zero, 750, 1500 and 2250 μM) and the third factor of gibberellin (zero, 750, 1500 and 2250 μM) with three replications in research greenhouses of University of Agricultural Sciences and Resources Natural Sari was done in 1397. Canola seeds were immersed in the solution of the mentioned salicylic acid and gibberellin treatments for 24 hours at a temperature of 25 degrees Celsius. After passing the desired period, the seeds were washed with distilled water and completely dried on filter paper, which were immediately cultivated after drying. Germination percentage, first day of emergence, last day of emergence, time spread of emergence, day to maturity, 1000-seed weight, number of pods per plant, plant height, pod length, number of seeds per pod and yield were measured. At the end, all statistical analyzes of the data obtained from this experiment, after ensuring their normality, were performed using SAS and SPSS software.

The results of analysis of variance showed that seed priming by salicylic acid and gibberellin treatments had a significant effect on all traits except pod length at the level of one percent. The interaction of genotype with salicylic acid and the interaction of genotype with gibberellin were significant for all traits. The interaction of salicylic acid with gibberellin and the triple interaction of gibberellin with salicylic acid with genotype were significant for all traits except pod length. The results of mean comparison showed that the use of seed priming of salicylic acid and gibberellin, with increasing germination percentage, reducing the range of emergence and decreasing the day to maturity caused early ripening in rapeseed. In addition, by increasing the yield components such as number of seeds per pod, number of pods per plant, 1000-seed weight, height and length of pods, also increased grain yield. The results also showed that the combined application of 1500 μM levels from both treatments (salicylic 1500 × gibberellin 1500) has the greatest effect on increasing yield components and grain yield, so that grain yield in Lord genotype from 7.5 (gram per pot) to 12.1 (gram per pot) And in Hayola 308 genotype increased from 4.1 (g/pot) to 6.89 (g/ pot).

In general, the results showed that among the different concentrations of treatment, lower concentrations of these treatments were more effective in inducing prematurity and increasing yield. And among the cultivars used, Lord genotype has a higher but late yield, which can be solved by treating the problem of late maturity and as the best genotype in terms of early maturity and high yield under the influence of treatments, especially at the level of 1500 salicylic acid × Gibberellin introduced 1500 μM

Germination and seedling establishment are critical and important stages in the life cycle of plants. Therefore, the study of germination and methods of breaking on seed dormancy in plants is of great importance. One of the corrective operations on improving the seed yield of rangeland plants is seed priming. Priming is an operation on the seed that causes the seed to absorb a sufficient amount of water to accelerate the germination process. Trifolium resupinatum is a clover. In this study, in order to germinate seeds from treatments of 100, 200 and 300 mM sodium chloride in 24, 48 and 72 hours, gibberellic acid 125 and 250 ppm during 12, 24 and 48 hours and 0.01 solution, 0.02 and 0.03% of potassium nitrate were used for 12 and 24 hours, respectively. Distilled water was also considered as a control treatment. The study was conducted in a randomized statistical design with 3 replications and two-way analysis of variance was used to analyze the data. Traits such as germination percentage, germination rate, germination index, shoot length, root length, number of germinated seeds, seedling length and seed vigor index were evaluated. The results showed that in the seed germination of Iranian clover species, three chemical treatments had better results in terms of yield of the germination process of the species than other treatments and were recommended as the most desirable pretreatments and potassium nitrate and then acid treatments. Gibberellins had the greatest effect on the seed Dormancy breaking.