parto roshandel

To evaluate the effect of seed priming with ascorbic acid to increase salt tolerance in Chenopodium quinoa var. Giza 1 during the vegetative growth period, the current research was conducted in the form of a factorial experiment (ascorbic acid at three levels of 0, 20 and 60 mM and NaCl at two levels of 0 and 400 mM) and based on a completely randomized design. The traits measured in the experiment were fresh and dry weight, concentration of photosynthetic pigments, hydrogen peroxide (H2O2) and malondialdehyde, and the activity of antioxidant enzymes. Data analysis showed salinity resulted in a significant decrease in the amount of dry weight (51.4%), fresh weight (65.6%) and total chlorophyll (55.8%). In addition, salinity increased the content of malondialdehyde (2.3 folds), hydrogen peroxide (2.5 folds) and the activity of antioxidant enzymes (catalase, ascorbate peroxidase and guaiacol peroxidase). However, seed priming with ascorbic acid at the best level (20 mM) alleviated the adverse effects of NaCl in this variety by increasing the fresh weight (44.7%), dry weight (51.4%), and protecting membrane integrity and photosynthesis activity. Also, the use of ascorbic acid by changing the activity of antioxidant enzymes and reducing the content of hydrogen peroxide caused a reduction in oxidative stress in in this variety. It can be concluded that seed priming of this variety with 20 mM ascorbic acid can be effective on its successful cultivation in high salinity levels.

In plants, melatonin (N-acetyl-5-methoxytryptamine) contributes to various environmental stress responses and developmental processes. Accordingly, the effect of seed priming with melatonin (1250 µM) on increasing salt tolerance at 40 dS m-1 NaCl was studied in Chenopodium quinoa var. Titicaca (quinoa) using a factorial experiment based on a completely randomized design at Shahrekord University in 2019. In the present experiment, different levels of NaCl and melatonin were first applied and according to the obtained results, 1250 μM melatonin and 40 dS m-1 NaCl were selected for the main study. The measured traits and indices included the fresh and dry weight, the content of photosynthetic pigments, hydrogen peroxide (H2O2), malondialdehyde (MDA), as well as the activity of catalase, ascorbate peroxidase, and guaiacol peroxidase. Seed priming with melatonin reduced the adverse effects of NaCl in the salt-stressed quinoa plants by increasing the dry weight (two-fold) and the level of photosynthetic pigments (1.2-fold) compared to the salinity stress alone. Also, the application of melatonin by changing the activity of antioxidant enzymes, reduced the content of H2O2 by 25% and MDA by 42%, which resulted in the reduction of oxidative stress in the quinoa plants under salinity conditions. Overall, it can be concluded that seed priming with an optimal level of melatonin can be a proper technique to increase salt tolerance in quinoa under highly saline conditions by reducing the harmful effects of salinity-induced oxidative stress by reducing the H2O2 and lipid peroxidation levels. It also protects the photosynthetic machinery by reducing the degradation of photosynthetic pigments which leads to the increased growth of the quinoa plants under salinity conditions.

To evaluate the effect of salicylic acid (SA) on seed germination of black bean plant under saline conditions, seeds were primed with salicylic acid (0, 2, 10, and 20 mM) and germinated under salt stress (0, 50, and 100 mM NaCl). The measured parameters included the percentage and rate of seed germination, seedling length and dry weight, malondialdehyde and hydrogen peroxide levels, and activity of catalase, ascorbate peroxidase and guaiacol peroxidase in the seedlings. Results showed the values of germination indices decreased with increasing the level of salt stress. However, SA priming (10 mM) alleviated the harmful effects of salt stress in black bean. SA increased seed germination percentage by 72% and 45% at 50 and 100 mM NaCl respectively, compared to the control condition. Germination rate augmented by 33% (at 50 mM NaCl) and 60% (at 100 mM NaCl) by SA priming compared to the seeds exposed to salt stress alone. Seedlings dry weight (+ 51% at 50 mM and + 34% at 100 mM) and length (+ 57% at 50 mM and + 29% at 100 mM NaCl) were significantly higher by priming with 10 mM salicylic acid, compared to exclusively salt stress-treated seeds. SA priming increased antioxidant enzymes activities and decreased the levels of lipid peroxidation and hydrogen peroxide in salt stressed black bean seedlings. In conclusion, salicylic acid priming (particularly at 10 mM) enhances salt tolerance in black bean via lessening of oxidative stress.

In order to study the effect of silicon nutrition to increase salt tolerance in black bean variety of Phaseolus vulgaris, 12-day-old seedlings were treated with NaCl (0 and 50 mM) and NaCl (50 mM) + silicon (0.5 or 3 mM) in the green house for four weeks. The analyzed parameters were fresh and dry weights, total chlorophyll and free proline concentrations, relative water content (RWC) and electrolyte leakage in the leaves, and the concentrations of Na+ and K+ in the shoots and roots. Salt stress decreased the values of fresh (39.3%) and dry weight (48.4%), total chlorophyll (20.9%), K+ (60.6% in the roots; 20.3% in the shoots) and RWC (50%). Moreover, the level of free proline (19%), electrolyte leakage (2.4 folds) and Na+ concentration (4.6 folds in the shoots; 3.8 folds in the roots) significantly increased. However, silicon (particularly at 3 mM) ameliorated the deleterious effects of NaCl. At this case and compared to exclusively salt stress, the fresh and dry weights were increased by 20.3 and 66%. Also, the content of total chlorophyll (21%), RWC (83%) and K+ (21% in the shoots, 90% in the roots) augmented, but electrolyte leakage (38%) and the content of Na+ decreased (39.7% in the shoots, 27.8% in the roots). Generally, current data suggested silicon enhanced salt tolerance in black bean plants by reducing the entrance of Na+ and maintaining the level of K+ in the salinized tissues. Besides, it improved the water status, membrane integrity and function of photosynthetic machinery under salinity.

In the present study, the effect of seed priming with magnetic field (MF; 45, 90, 200 and 250mT for 5, 10, 20 and 30 min) was evaluated in 60-day-old Hyssopus officinalis plants grownunder 8 days irrigation intervals. The assessments were consisted of biomass, membranestability, photosynthetic pigments concentrations, polyphenols content, antioxidant enzymesactivities and antioxidant capacity. In comparison with the exclusively water-stressed plants,MF-priming significantly altered these parameters, particularly at 200 mT/5 min. At thisintensity, the level of biomass, total chlorophyll and polyphenols content increased by 2.2, 2.5and 7.7 folds, respectively. Furthermore, electrolyte leakage and MDA content decreased by35 and 33%. Reducing power, DPPH and superoxide anion scavenging activities highlyaugmented by MF. MF-priming at 200 mT increased catalase (+92%) and ascorbateperoxidase (+2.3 folds) activities. But, the highest activity of guaiacol peroxidase wasrecorded for MF-primed H. officinalis at 90 mT. In conclusion, seed priming with MFincreases drought tolerance in H. officinalis through protection of cellular membrane integrity,maintenance of photosynthetic pigments content and also alternation of antioxidant enzymeactivities. It also improves medicinal properties of the shoots via increasing polyphenolsconcentration and antioxidant capacity.

To evaluate the effects of NaCl priming to increase salt tolerance in Dracocephalum moldavica L. an experiment was conducted as factorial based on completely randomized design at Shahrekord University.

Seeds of medicinal plant D. moldavica were primed with NaCl (1 M/ for 24 h/ at darkness/ under 25˚C) and then 30-day-old plants were introduced to salinity (0, 100 and 150 mM NaCl) for one month. The analyzed parameters consisted of dry weight, leaf area, total water content, leaf relative water content, electrolyte leakage, lipid peroxidation, photosynthetic pigments concentrations, total phenolic content and the activity of antioxidant enzymes.

NaCl-priming alleviated the injurious effects of salinity in the salinized plants. The biomass increased up to 64.5% and 3-fold at 100 and 150 mM NaCl, compared to exclusively salinity. Ion leakage and lipid peroxidation decreased as well. Moreover, NaCl-priming led to increase leaf area, improve water status, photosynthetic pigments content and antioxidant enzymes activities in favor of improving the biomass of salinized D. moldavica. Total phenolic content increased by salinity alone, but NaCl-priming markedly decreased it at normal condition. The pattern of polyphenols concentration and accumulation was different under NaCl-priming + salinity treatment.

Limitations:

 No special limitations were founded. 

Originality/Value:

Seed priming with NaCl enhanced salt tolerance in D. moldavica through improving water status and photosynthesis, protection of cellular membrane integrity and changes in antioxidant enzyme activity. Alternation in polyphenols concentration might be a signature of changes in the medicinal properties of different parts of this medicinal plant.

In the present study, improvement of salt tolerance in basil (as a salt-sensitive plant) was investigated through silicon (Si) nutrition. Basil plants were subjected to silicon (0, 3 mM) and salinity (0, 50, 100, 150 and 200 mM NaCl) for a duration of one month. Salt stress significantly decreased the biomass of basil. Si supplement (3 mM) resulted in a considerable increase (averagely +135%) in the biomass of salinized plants. Salt stress significantly decreased photosynthetic pigments concentrations, but Si supplement improved total chlorophyll concentration (averagely up to +217% compared to salinized plants). This improvement in pigment concentrations also occurred for carotenoids content (+123%). Salinity increased lipid peroxidation and H2O2 level in the aerial parts of the basil plants, but Si decreased lipid peroxidation (-49.1%) and H2O2 content (-29%) under salinity condition. Results showed salinity (alone) or together with Si, increased the level of polyphenols and also the level of radical scavenging activities in the aerial parts of basil but this effect was much more in plants co-treated with Si and salinity. Si nutrition increased the activity of SOD, APX and GPX in response to salt stress, but it did not affect CAT activity. Overall, Si supplement could induce salt tolerance in basil plants by improving photosynthesis, membrane integrity, and detoxification of toxic radicals. Furthermore, silicon increased the medicinal properties of basil via elevating its antioxidant capacity under salt stress.

Pistachio suffers from some physiological disorders such as fruit abscission, endocarp lesion, blankness, non-split, early-split and deformed nuts. In this experiment, the effects of calcium nitrate (2 gr/lit), calcium chloride (2 gr/lit), boric acid (200 ppm) and their combination treatments were investigated on physiological disorders of ‘Kaleh-Ghoochi’ pistachio. Foliar application was applied one week earlier and two weeks later than full bloom. Then, physiological disorders and enzyme activities, such as catalase (CAT), poly phenol oxidase (PPO), peroxidase (POD), phenylalanine ammonilyase (PAL) and total phenol level of nut-shells and proline level of leaves were tested. Results specified that all applied treatments diminished fruit abscission. Also, all treatments, excepting boric acid, diminished endocarp lesion and non-split nut disorders but there were no considerable differences between the treatments. Results specified that all applied treatments decreased the blank nut but there were no considerable differences between the treatments. In this research, the lowest deformed nuts with 10.38 percent and early split nut with 2.48 percent were observed by application of both calcium nitrate and boric acid. Meanwhile, the highest split nuts with 56.55 percent were obtained by application of calcium nitrate and boric acid. Generally, all treatments especially use of both calcium nitrate and boric acid diminish the catalase, poly phenol oxidase, peroxidase, and phenylalanine ammonilyase enzymes activities and moreover total phenol of nut-shells and proline of leaves.

In order to evaluate the effects of seed priming with salicylic acid (SA) (0, 2, 10, and 20 mM) to increase salt tolerance (0, 50, 100, 150, and 200 mM NaCl) in medicinal plant Dracocephalum moldavica at seed germination, an experiment was conducted as factorial in a completely randomized design with four replicates. The assessed parameters included germination percentage and rate, length, dry weight, lipid peroxidation, electrolyte leakage, and the activity of catalase, ascorbate peroxidase, and guaiacol peroxidase of the seedlings. Results revealed the values of germination indices significantly decreased with increasing salinity levels. Nevertheless, seed priming with SA (2 mM) significantly mitigated the adverse effects of salinity in D. moldavica. Under salinity and at this level of SA priming, seed germination percentage increased by 24% and 75% at 100 and 150 mM compared to exclusive salt stress. Also, germination rate augmented by SA priming up to 9.2% at 100 mM and 2 folds at 150 mM NaCl. The values of weight (+ 9.1% at 100 mM and +8 folds at 150 mM) and length (+12.5% at 100 mM and + 15.1% at 150 mM NaCl) of seedlings significantlyincreased by SA priming compared to the exclusively salt-stressed ones. SA priming increased antioxidant enzymes activities while it decreased the level of lipid peroxidation and ion leakage in the seedlings of D. moldavica. As a conclusion, SA improved seed performance in D. moldavica under salt stress by reduction of detrimental effects of oxidative stress.

In order to protect environment and improve plant growth under drought stress conditions, an experiment was conducted as factorial in a completely randomized design with three replications on Niger )Guizotia abyssinica (L.F) Cass( seed at the research greenhouse of Shahrekord University in 2015. Physically pre-treatment as a seed placement in different magnetic field intensities including 0, 50, 100, 150 and 200mT (at 5 minutes time) as the first factor and  irrigation intervals at three levels of 2, 4 and 6 days as the second factor were considered. The effect of magnetic field, drought stress and their interaction were significant on all of the evaluated characteristics. The maximum root dry weight in 150mT field intensity under 2 days irrigation intervals, the maximum leaf dry weight, root length and number of flower in 100mT field intensity under 2 and 6 days irrigation intervals, respectively, the maximum content of chlorophyll a and (a+b) and carotenoids in 50mT field intensity under 6 days irrigation intervals, the maximum content of chlorophyll b in 150mT field intensity under 4 days irrigation intervals and minimum malondialdehyde content in 200mT field intensity under 2 days irrigation intervals were obtained. The maximum number of flowers (as the most important index on increasing yield) were obtaind at 200mT fields intensity for 2 and 4 days and at 50 and 100mT fields intensity for 6 days irrigation intervals. In general, it can be said application of magnetic field with moderate intensities can alleviate stress conditions.

In order to study the effects of magnetopriming on the physiological and phytochemical characteristics of Hyssopus officinalis plants, this research was conducted as a factorial experiment in a completely randomized design. Results showed that magnetopriming (particularly at 200mT/5 min) increased the level of shoot dry weight (82.6 percent), root dry weight (86.5 percent), total chlorophyll (32.8 percent), carotenoids concentration (32.4 percent) and polyphenols content (2 folds) in 60-day-old Hyssopus officinalis. Also, electrolyte leakage and lipid peroxidation decreased by 27.6 and 45 percent, respectively. In addition, reducing power, DPPH and superoxide anion scavenging activities significantly augmented. However, higher activities of superoxide dismutase (76 percent), catalase (4.2 folds), ascorbate peroxidase (2.4 folds) and guaiacol peroxidase (48 percent) were found at 90 mT. Results suggested that the application of magnetopriming promoted growth in H. officinalis through augmentation of cellular membrane integrity as well as biomass and photosynthetic pigments content. Furthermore, it was found to enhance the antioxidative system. Magnetopriming might apparently improve the medicinal properties via increasing the level of polyphenols and antioxidant capacity in H. officinalis.

In order to study the diverse effects of seed priming with 24-epibrassinolide (EBL) (0, 0.1, 1 mg/l) to increase tolerance of tomato plants (Lycopersicon esculentum Mill.) to salinity (0, 70 and 140 mM NaCl), the experiments were conducted as factorial based on completely randomized design at greenhouse condition. Results showed that salt stress significantly decreased the growth of tomato plants. However, priming with EBL (1 mg/l) significantly decreased the negative effects of NaCl (particularly at 140 mM). At this case, EBL increased the fresh and dry weights (<2 folds), total chlorophyll (+72%), carotenoids (+ 2 folds), free proline (+3 folds), electrolyte leakage (-18.6%), Na+/K+ in the roots (-57.5%) and shoots (-62%) compared to salinity control. Generally, it could be concluded that priming with epibrassinolide resulted in enhanced salt tolerance in tomato plants via increment in free proline, photosynthetic pigments and decrease in electrolyte leakage and Na+/K+ ratio in the tissues.

The use of nanotechnology as a diverse and applied discipline is ongoing in almost all areas of science. Fertilizers and nano-nutrients have the effective properties which help the production of plants depending on their needs to regulate the plant growth. Plants under stress conditions are willing to produce natural nanoparticles to continue their growth. Nano TiO2 has a high photocatalytic effect and as a catalyst, it is mainly used in water, electronic devices, conversion and storage equipment of Energy as suspension. Sources of SiO2 are very diverse, including natural nanoparticles, anthropogenic particles and engineering nanoparticles. Although, silicon in many crops is not an essential element for growth, it has beneficial effects on plants growth and development. Today, carbon nanotubes are one of the most important materials in industrial programs. These materials, with different methods and specific properties, can play an important role in the production of composite materials, application in medicine, electronic and energy storage. The Niger plant, with the scientific name of Goizotia abyssinica (L.F) Cass, belongs to the Asteraceae family. Its seed, are used in pharmacy, food industry, green manure and for feeding birds and cows. Therefore, the purpose of this experiment was to investigate the effect of type and concentration of three nanoparticles on some of germination characteristics and anthocyanins content in Niger medicinal-oily plant.   In order to evaluate the effect of three nanoparticles on seed germination of Niger, an experiment was conducted as factorial in a completely randomized design with four replications. The treatments of TiO2, SiO2, and CNT were as the first factor while their concentrations in four levels (zero, 10, 30 and 60 mg/l) were as the second factor. In this study the traits of germination percentage, germination rate and mean of daily germination, germination and vigour index, length, fresh and dry weight of radicle and plumule, anthocyanin content and radicle resistance percentage were measured.    The germination percentage, germination rate and mean of daily germination decreased by increasing of nanoparticles concentration. The favorable effect of TiO2 on germination index at the concentration of 30 mg/l and radicle dry weight at the concentration of 10 mg/l, was gained compared to control. The positive effect SiO2 on germination index and radicle dry weight at the concentrations of 10 and 60 mg/l, the anthocyanin content and the fresh and dry weight of plumule at the concentration of 60 mg/l was obtained compared to control. Also, the appropriate effect of CNT on germination index at the concentration of 10 and 30 mg/l, the anthocyanin content and radicle dry weight at the concentration of 60 mg/l and plumule fresh weight at the concentration of 30 mg/l, was observed. According to the results of this study, it seems that the effect of nanoparticles in plants, in addition to the plant, species, type and concentration of nanoparticles, varies depending on the growth stage and physiology of the plant. It seems that nanoparticles at some concentrations can increase the water absorption of seeds and increase seedling growth with their positive effects. Anthocyanins are produced by exposure to stress due to their antioxidant activity. In general, it can be stated that increasing the concentration of nanoparticles caused and increased the oxidative stress in plant. Therefore, it is recommended by investigating the bad effects of nanoparticles on plants, if necessary, use nanoparticles at low concentrations (less than 60 mg/l) to increase the plant's efficiency.   Highlights: The effect of nanoparticles kind and concentration on seed germination indices and anthocyanin content of Niger seedling. Investigating the interaction of nanoparticle type and concentration as the physical priming factor of seeds on seed germination of multi-purpose Niger plant.

In the present study the effects of Si (0. 5 and 1 mM) have been investigated in two varieties of Phaseolus vulgaris (pinto bean and green bean) subjected to salinity (50 mM). Two series of experiments were separately arranged in completely randomized design for each of bean varieties and 12-day-old seedlings were introduced to the treatments which lasted for four weeks. The evaluated parameters were dry matters of the shoots and roots, total chlorophyll contents, membrane electrolyte leakage, proline and relative water content of leaves, Na+ and K+ concentrations in the shoots and roots. The results indicated salt stress significantly decreased biomass, K+ level, total chlorophyll and relative water content of leaves, whilst the concentration of Na+, proline and membrane electrolyte leakage increased. Si nutrition caused a marked increment in percentage of biomass in pinto bean which it was more than that of in green bean. Data analysis suggests Si increases salt tolerance in pinto bean by relatively blocking of Na+ entrance along with increasing relative water content of leaves and decreasing membrane electrolyte leakage in the leaves.

In order to evaluate the effect of water deficit stress on seed yield and yield components of safflower genotypes (Carthamus tinctorius L.), an experiment was conducted as a split plot with three replicates at the research filed of University of Shahrekord in spring 2016. Treatments consisted of three levels of irrigation based on 100%, 75% and 50% of the plant’s water requirement and three selected safflower genotypes including Sina, Isfahan and Faraman. Results indicated that deficit irrigation caused a significant reduction in all traits including the number of lateral branches per plant, plant height, head number per plant, number of seed per head, seed thousand weight, seed yield, oil percentage, oil yield, biological yield and harvest index. The lowest values of seed yield (1196 kg.ha-1) and oil yield (313 kg.ha-1) were obtained in the deficit irrigation treatment of 50 %plant water requirement and the highest seed yield (2310 kg.ha-1) and oil yield (561kg.ha-1) were obtained in 100% plant water requirement. The results showed that there was a significant difference among investigated safflower genotypes, and the highest seed yield (1998kg.ha-1) and oil yield (561kg.ha-1) were obtained in Sina genotype and the lowest seed yield (1659kg.ha-1) and oil yield (426 kg.ha-1) were obtained in local Isfahan genotype. The results showed that the differences among genotypes in terms of morphological traits, oil percentage, and oil yield were important components that could be used to select genotypes or appropriate cultivars with drought conditions.

In order to study the effects of seed priming by ascorbic acid (0, 40, 60 and 80 mM) to increase salt tolerance (0, 100, 150 and 200 mM NaCl) in moldavian balm at germination stage, an experiment was conducted as factorial in a completely randomized design with three replicates at Shahrekord University (2015 year). Evaluated parameters consisted of germination indices (germination percentage and rate, length and dry weight of seedlings and seed vigor index) and the activity of catalase, ascorbate peroxidase and guaiacol peroxidase. Results showed the values of germination indices significantly decreased with increasing salinity degree. However, seed priming by ascorbic acid (40 mM) decreased the negative effects of NaCl on germination of moldavian balm. At this level of priming and under 100 mM NaCl, seed vigor index increased by 32% and at 150 mM NaCl it increased by 2.7 folds. Since the activity of antioxidant enzymes was in coordinate with the effect of optimal concentration of ascorbic acid under salt stress, it is concluded that priming with ascorbic acid decreases oxidative stress due to NaCl by enhancing the activity of antioxidant enzymes in the tissues of moldavian balm and consequently salt tolerance increases in this plant at seed germination.

Extended abstract Niger with the scientific name of Guizotia abyssinica (L.F.) Cass. belongs to the Asteraceae family. Niger seed contains 50-75 percentage of oil which is used in the treatment of rheumatism and burns, and as a substitute for olive oil. Its meal is also used for animal feeding. Environmental crises sustained by living systems are considered as stress. Drought stress is one of the non-biological stresses. Yield reduction due to this type of stress is reported to be higher than that related to other stresses. Since plant development starts from germination and for survival, the seeds should germinate to adapt themselves to the environmental conditions and establish themselves in the soil, the success of passing the germination stage will play an important role in other stages of plant establishment. Different studies have shown the positive effect of magnetic field on increasing germination characteristics. In this regard, applying a magnetic field before planting is a safe and inexpensive method for increasing germination and seedling growth. Seed priming is useful for a faster and more powerful response to drought stress and among different types of priming, physical priming is of particular importance for ecological reasons and for not having a negative impact on the environment. In order to study the effect of seed physical pre-treatment and drought stress on seed germination characteristics of Niger, an experiment was conducted as factorial in a completely randomized design with three replications at the Research Laboratory of Seed Science and Technology at Shahrekord University. Different magnetic field intensities at five levels including (0, 50, 100, 150 and 200 mT (at 5 minutes period)) as the first factor and drought stress at five levels (0, -4, -5, -6 and -7 bar Polyethylene Glycol6000) as the second factor were considered. The results of variance analysis showed that the effect of drought stress, magnetic field intensity and their interaction were significant on all of the evaluated characteristics. The maximum germination percentage and rate and the minimum of T10 and T50 were observed in 50 mT field intensity under normal conditions. The minimum germination index under normal conditions and the maximum length and shoot dry weight under non-treatment conditions and the maximum root and shoot fresh weight in 200 mT field intensity under normal conditions were obtained. The maximum root length and dry weight were observed in 50 and 100 mT field intensity under normal conditions, respectively. Seeds which cross through a magnetic field, become swollen and probably as a result, the activity of auxin hormone in these seeds increases. In addition, the respiration level also increases in them and they have higher levels of energy and activity, which results in faster and more uniform germination and the creation of stress-resistant plants. In this study, although by increasing drought stress intensity, negative effects were observed on germination characteristics, the magnetic field under these conditions improved some germination characteristics. In general, for the purpose of improving germination and alleviating drought stress conditions, for 0, -5 and -7 bar potentials, the field intensity of 50 mT and for -4 and -6 bar potentials, the field intensity of 150 mT are recommended.

Highlights: The effect of magnetic field on germination of multipurpose seed of Niger plant.
The effect of drought stress on germination of multipurpose seed of Niger plant, given Iran’s being located in dry belt.
The positive effect of magnetic field on germination of Niger seed to improve the negative effects of drought stress.

Seeds of medicinal plant Artemisia sieberi were pretreated with H2O2 (0, 10, 50, 90, and 140 μM) and grown in saline condition (0 and 150 mM NaCl) for one month. Phytochemical properties such as antioxidant capacity and also salt tolerance in the plans arising from H2O2 pretreated seeds under salt stress were examined. Results showed a decrease in H2O2 and malondialdehyde concentrations in the shoots of pretreated A. sieberi. Furthermore, seed pretreatment with H2O2 (particularly at 50 μM) increased photosynthetic pigments content, antioxidant capacity and dry and fresh weights of shoots in the pretreated plants under both normal and saline conditions. The activity of the antioxidant enzymes increased in all pretreated A. sieberi plants particularly at 50 μM H2O2. Data indicated H2O2pretreatment can induce salt tolerance in A. sieberi by supporting physiological and phytochemical processes such as photosynthesis, reactive oxygen species scavenging and detoxification, and also membrane stability in this species. Additionally, hydrogen peroxide pretreatment enhanced reducing power and antioxidant activity in A. sieberi suggesting an increase in its medicinal properties.

Fruit abscission is one of the disorders in pistachio trees. Pistachio trees produce plenty of flowers, but only parts of the flowers are pollinated and set fruit. Environmental stresses and inadequate nutrition especially during flowering time have increased fruit abscission. This disorder by reducing the yield of pistachio led to economic loss. Yet, little research has been carried out on fruit abscission in pistachio. In order to evaluate the effects of foliar treatments with calcium nitrate (2 gr/lit), calcium chloride (2 gr/lit), boric acid (200 ppm) and their combination treatments were studied on fruit abscission of ‘Kaleh- Ghouchi’’ pistachio. Treatments were applied one week before and also two weeks after full bloom. The experiment was conducted by using a split plot base on a completely randomized block design (CRBD) with 5 replicates per treatment on 13-year-old ‘Kaleh - Ghouchi’ pistachio trees grafted on Badami- Riz rootstock. The selected trees were “on” years. Two weeks after full bloom, in each cluster, the number of fruits were counted and fruit abscission was studied in three different stages at intervals of 15 days and in each stage of the test, the disorder fruits were dissected and embryo condition was studied by binocular too. The results showed that at all of the stages, dissected fruit have the embryo and no observed blanking fruit. Also, the results showed that all applied treatments in all three stages of evaluation decrease the fruit abscission as compared to control and Just boric acid treatment in the third stage of evaluation as compared to control have no superiority. While there were no significant differences between other treatments. In relation to the effect of treatments on the absorption of elements, results showed that the concentrations of calcium, boron, and nitrogen were different in treated and control trees. Treated trees with calcium nitrate + boric acid and calcium nitrate were absorbed the highest amount of calcium. Also treated trees with calcium nitrate + boric acid and boric acid, was absorbed the highest amount of boron. While treated trees with calcium nitrate + boric acid and calcium nitrate, was absorbed the highest amount of nitrogen. In this experiment, calcium nitrate + boric acid treatment was more effective than other treatments in improving yield traits.

Recent studies have introduced seed priming with H2O2 as an effective technique to alleviate abiotic stresses in plants. In the current study, accomplished at Faculty of Sciences, Shahrekord University, seeds of medicinal plant Artemisia aucheri were primed with H2O2 (0, 10, 50, 90 and 140 µM) and grown under salt stress (0 and 150 mM NaCl) for one month. Results showed a decrease in H2O2 and malonyldialdehyde concentrations by H2O2 priming leading to diminish lipid peroxidation at the cellular level. Moreover, seed priming with H2O2 (particularly at 90 µM) increased biomass, total water content, chlorophyll (a) and carotenoids concentrations, total phenolic content and antioxidant capacity in the plants from primed seeds under both normal and saline conditions. Higher activities of superoxide dismutase and catalase were observed in the primed A. aucheri with 90 µM H2O2, while the activity of ascorbate peroxidase was at the maximum level at 140 µM H2O2 priming condition. Additionally, hydroxyl and super oxide radicals scavenging activities were at the maximum level in the plants from primed seeds with 90 µM H2O2. Data revealed that H2O2 priming can induce salt tolerance in A. aucheri plants by adjusting physiological and metabolic processes such as photosynthesis, ROS scavenging and detoxification and brings about an improved growth and development in this species. Furthermore, H2O2 priming at 90 µM augmented antioxidant activity and reducing power in A. aucheri suggesting an increase in its medicinal properties.

In the current work, the effect of magneto-priming has been studied on seed germination of hyssop (Hyssopus officinalis L.) - a medicinal plant from Lamiaceae - in normal condition and osmotic stress. Dehydration is a consequence of osmotic stress. The primed seeds with magnetic field (45, 90, 200, 250 mT) upon different times (5, 10, 20 and 30 min) were allowed to germinate and grow in Petri-dishes for 10 days under normal condition or osmotic stress due to mannitol (100, 200, 300 mM). At these experiments, rate and percentage of germination, length and dry weight of shootlet and rootlet of seedlings and seed vigor index were evaluated. Magnetic field (MF) (200mT/5min) significantly increased percent germination (%) and seed vigor index (%) at normal condition. Moreover, MF significantly increased seedling dry weight (25%) and rootlet length (36%). Under osmotic stress, MF significantly augmented seed germination percentage by 14%. It would be concluded that at normal condition, seed priming of H. officinalis with optimal MF could increase percent germination and promote rootlet growth which subsequently causes to improved growth through stronger establishment of seedlings and higher water absorbance from medium. Furthermore, MF would be effective for early growth of H. officinalis via enhancing seed germination under osmotic stress and/or water stress.

Saltbush (Atriplex leucoclada) is one of the endemic halophyte plants of Iran, useful for desertification, restoring and modifying rangelands in arid and desert areas cultivation. To assess the effects of mechanical and chemical treatments in break seed dormancy and to stimulate seed germination in dimorph seeds of Atriplex leucoclada, two tests were performed in completely randomized design with three replicates for both of its two seed types. Treatments were: scratch pre-treatment, gibberellic acid or kinetin, ethephon, potassium nitrate or thiourea all performed for 24 h or 48 h at 4˚C or 20˚C, pre-treatment running water, moist chilling (20 days/4˚C) + 14-days treatment with gibberellic acid or potassium nitrate or thiourea, scratching with a sand paper, making a gap with a needle, hot water (70˚C or 90˚C for 15 min), sulphoric acid (75%), dry-storing (3 months/20˚C), stratification (3 months/4˚C). As the twice-scratched pretreatment caused the highest germination percentage (73.3%) and vigour index (8860) in the brown seeds and for the black ones these values were 63.3% and 7710, respectively. Overall, it is concluded the seed dormancy in both types of seeds in A. leucoclada could be physical.