فصلنامه فرآیند و کارکرد گیاهی
سال دوازدهم شماره 2 (پیاپی 55، خرداد و تیر 1402)

One of the strategies to increase the tolerance of plants to environmental stress conditions, including drought stress, is to improve the process of receiving nutrients by plants. Arugula (Eruca vesicaria subsp. sativa Mill.) is cultivated as a leafy vegetable in Hormozgan province. Considering the limitation of water resources in this province and the role of fertilizers in increasing the tolerance of vegetables to drought stress, this research was conducted to investigate the biochemical, vegetative, yield and efficiency indicators responses of arugula to fertilizer sources under deficit irrigation conditions, a split plots experiment as a completely randomized design with 12 treatments and three replications in the greenhouse of University of Hormozgan. The experimental treatments included irrigation as the main plot (full irrigation as control, moderate and severe deficit irrigation) and the use of different fertilizers as sub-plot (control, urea, vermicompost and cow manure). The results showed that all the biochemical traits including the chlorophyll and carotenoids contents, catalase and peroxidase activities and the amount of malondialdehyde, vegetative and yield traits including plant height, root length and diameter, root and shoot fresh weight, fresh economical yield and nitrogen and water use efficiency of Arugula was significantly affected by the main effect of irrigation. While the main effect of fertilizer sources on peroxidase activity, plant height and root diameter were not significant. The use of different fertilizers improved the under-study traits under deficit irrigation conditions, and in most cases the efficiency of organic fertilizers was higher than urea. So that the use of vermicompost increased the catalase activity in severe and moderate deficit irrigation conditions by 23.3 and 29.9 %, respectively. Moderate and severe deficit irrigation, as well as the use of fertilizer, increased the water use efficiency in arugula. At each fertilizer level, severe deficit irrigation caused a significant decrease in nitrogen use efficiency compared to full irrigation and moderate deficit irrigation. The results of this research showed that in severe deficit irrigation conditions, the use of cow manure increased the economic yield of arugula by 52.0% compared to the control. In total, the highest economic yield was obtained in the full irrigation and the use of urea or cow manure. Therefore, according to the limitation of water resources in Hormozgan province, the application of fertilizer can improve the yield of arugula under deficit irrigation conditions.

Calendula officinalis L. is an annual plant of the Asteraceae family that has medicinal, food and ornamental uses. In order to evaluate the effect of melatonin on some morphological and physiological characteristics of Calendula officinalis L. under salt stress, a factorial experiment was conducted using a completely randomized design with three replications. In this study, the effects of 5 levels of salinity (0, 40, 80, 120 and 160 mM sodium chloride) and two levels of foliar spraying of melatonin (0 and 100 μM) were evaluated. The results showed that salinity stress caused a decrease in all the investigated parameters in C. officinalis L. under salinity stress. The results of variance analysis of the data showed that salinity stress has a significant effect (p ≥ 0.01) on all measured parameters except chlorophyll b and anthocyanin. However, melatonin caused a significant increase (p ≥ 0.01) in a number of morphological (number of leaves, number of flowers, length of shoots, fresh and dry weight of shoots) and physiological parameters (relative water content, chlorophyll a, total chlorophyll, carotenoids, total protein and total phenol). The results of this study showed that salinity stress reduced the morphological and physiological characteristics compared to control, while the use of melatonin improved the morphological and physiological characteristics of the Calendula officinalis L., and melatonin can be used to moderate the negative effects of stress.

Tomatoes are known as one of the most consumed food crops among the common vegetables in the world. Since tomatoes are highly perishable, there are many problems in their transportation, storage and marketing. This research was conducted with the aim of investigating the effect of carrageenan and spermidine treatments on the physiological and biochemical properties of Lycopersicon esculentum cv. Teena. This factorial experiment was performed in a completely randomized design, at two storage temperatures 12 and 27 ºC, with three repetitions. Ripe green fruits were treated with concentrations of 0, 2 and 4 ppt λ-carrageenan and 0, 1 and 2 mM spermidine by immersion and for 10 minutes. The storage period was considered as two months. By measuring some characteristics during storage, it was found that the highest amount of titratable acidity was obtained by treating the fruits with 1 ppt carrageenan at a storage temperature of 12 ºC, and the highest firmness of the fruit tissue, ascorbic acid, lycopene and the lowest amount of total dissolved solids, percentage of fruit weight loss, polygalactronase and pectin methylesterase activity in fruits treated with λ-carrageenan 4 ppt at the temperature of 12 °C. The results of this experiment indicate that the carrageenan solution of 4 ppt and 12 °C can be introduced as a useful treatment to maintain the quality of the stored tomato fruits.

The Valerian plant (Valeriana officinalis L.) is one of the most important medicinal plants known in the world and native to Europe and Asia, which has been considered and used by humans in traditional medicine since ancient times. In this study, in order to evaluate the effect of inoculation with Funneliformis mosseae and drought stress on some characteristics, including growth parameters, osmotic adjustment and phosphorus uptake of valerian plant, a factorial experiment was conducted in a completely randomized design with 4 replications for two months. The experimental factors included two fungi levels (non-inoculated (control) and inoculated) and three levels of drought stress (90-100% (control), 60-70%, and 40-50% of field capacity (FC)). The results showed that drought stress significantly reduced the biomass, leaf relative water content, and phosphorus concentration of shoot and root at both 60-70% FC and 40-50% FC levels, and the chlorophyll content at 40-50% FC level. In this research, growth parameters, chlorophyll content and phosphorus concentration increased due to colonization with F. mosseae at both stress levels. Biochemical analyses also showed that the contents of soluble sugars, protein and malondialdehyde (MDA) in the shoots and roots of valerian significantly increased under drought stress. Mycorrhizal inoculation of valerian caused an increase in shoot protein at 60-70% FC level and conversely, it caused a decrease in the contents of soluble sugars and MDA in shoot and root and protein of root at both 60-70% FC and 40-50% FC levels compared to non-inoculated plants. In general, the colonization of valerian plants with F. mosseae by modulating the effect of drought stress could be a suitable and efficient method to mitigate the detrimental effects of drought stress on the symbiotic plants.

The present experiment was aimed to investigate the improvement of salt tolerance in narcissus by exogenous application of sodium nitroprusside (SNP) in a factorial complete randomized block design with three replications at the Research Greenhouse, Islamic Azad University, Isfahan (Khorasgan) Branch during 2019-2020. Experimental treatments included irrigation by saline water at two levels 4 and 8 dS m-1 and control (without saline), as well as SNP (0, 100, 200, and 400 µM). The results indicated that elevated salt stress levels induce oxidative stress, including an increase in the hydrogen peroxide by 82% and malondialdehyde by 118% in plants. Severe salt stress reduced morphological traits, including a 40% decrease in flower longevity on the plant and a 49% decrease in the flowering duration of narcissus compared to non-stress conditions. The salt stress led to the change of antioxidant enzymes activities at different concentrations. The activity of superoxide dismutase enzyme positively correlated with salt treatment and increased up to 23%. While catalase enzyme increased up to 4 dS m-1 treatment by 87% and then decreased at a higher concentration in the leaves. However, SNP reduced oxidative damage in plants by improving antioxidant enzymes, proline and flavonoid content, ultimately, preventing the reduction of plant biomass. Finally, the present study showed that the exogenous application of SNP, especially at a concentration of 200 µM, improved narcissus tolerance to salinity stress by reducing the uptake of Na by 16%, as well as decreasing membrane lipid peroxides by 17%.

Medicinal plants contain valuable active compounds that are produced in limited quantities under natural conditions, so the use of methods such as tissue culture and stimulant materials is useful to produce more secondary metabolites in medicinal plants. In this study, the effects of methyl jasmonate and LED lights as two elicitors on physiologic and secondary metabolites in the roots of 30-day-old licorice seedlings in MS media were investigated. In this study, concentrations of zero, 0.2, 0.5, 1 and 2 μM methyl jasmonate as well as blue, red and blue+red light treatments, were used in three replications in a completely randomized design. The results showed that flavonoid content at wavelengths of 300 nm at a concentration of 1 μM methyljasmonate showed a significant increase compared to the control. According to results, the amount of phenolic compounds in methyl jasmonate treatment increased at a concentration of 1 μM and in blue light treatment. The highest activity of phenylalanine ammonialyase was observed in blue light, but the greatest amount of glycyrrhizin (12.10 µg/g FW) was recognized in red light treatment. Also, red light significantly increased the growth and proliferation of plants compared to other treatments. In general, it can be concluded that the use of stimulants such as methyl jasmonate and red and blue lights increases the amount of secondary metabolites in medicinal plants.

It is very important to find ways to increase the tolerance of plants under drought stress conditions. In order to study the effect of drought stress levels and types of humic fertilizers, amino acid and organic supplements on quantitative and qualitative traits of safflower (Goldasht cultivar), an experiment was conducted as split plots base on randomized complete block design with three replications at the research farm of Zabol University (Chah Nimeh). The main factor of irrigation cut-off levels based on plant growth stages: control (full irrigation), irrigation up to the main stem formation stage and irrigation up to the stage of flowering completion and the secondary factor of five levels of fertilizer treatment: Control (not applicable), amino micropower fertilizer, humic acid, humica and organic supplements in amounts of two per thousand. Maximum plant height (69.76 cm), number of leaves per plant (78.43), number of branches (6.2), oil content (34.2), chlorophyll a, b and carotenoids (11.51, 3.37, 2.40 mg/g fresh weight respectively) was obtained from foliar application treatment with humic acid and complete irrigation. Percentage of changes in plant height (27.7), number of leaves (19.5), number of branches (35.5), petal weight (50), oil content (48), chlorophyll a, b, carotenoids (respectively 33, 38 and 27) under complete irrigation and foliar application of humic acid due to severe stress and non-application of fertilizers. Catalase enzyme activity (97%), peroxidase (99%) and Protein content (62%) increased due to stress and foliar application of humic acid. In general, it seems that foliar application of humic acid compared to other organic fertilizers used in this study can achieve better results under drought stress conditions.

Deterioration is an irreversible feature of the seed that threatens its viability. Seed priming is one of the methods which improves vigor by modifying the structure and performance of deteriorated seeds. In this regard, at the first step, the best priming combination of different concentrations of salicylic acid, thiourea, and gum arabic was selected by germination and seedling traits in deteriorated seeds of canola var. Okapi. Then, using conventional experimental designs, its effect was tested on germination indices, seedling growth, antioxidant enzymes' catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GP), and alpha-amylase (α-amylase). The results of the Taguchi method introduced a combination of 1 mM salicylic acid and 0.75% gum arabic as the best treatment, and its effectiveness was confirmed by subsequent experiments. The stimulating effect of this treatment on germination rate, root and seedling length, and seedling weight was significant compared to the control treatment (p≤0.01). The length and weight of seedlings increased by 30 and 60%, respectively. Enzymatic results showed that the activity of SOD, APX, and α-amylase enzymes was significantly (p≤0.01) increased by the selected treatment by 14, 22.7, and 5.5%, respectively, compared to the control treatment. In general, priming the seeds with a combination of salicylic acid and gum arabic stimulates the defense system and remobilization of reserves, which is reflected in the improvement of germination and seedling indices. Enhancing these factors provides a suitable condition for the optimal establishment of canola in environmental conditions.

Spermine (Spm) is a group of polyamine compounds that has four groups of nitrogen (tetraamine) and therefore has a higher buffering capacity that is capable of enhancing plant defense systems against many environmental stresses. In this study, which was conducted in 2016 in the research greenhouse of the Graduate University of Advanced Technology, the protective effects of Spm pretreatment against the toxicity of salinity were investigated in pumpkin. For this purpose, Spm was added at 0.1 and 1 mM to the hydroponic medium for 5 days before stress. Salinity treatment (NaCl) was applied at three levels of 0, 40 and 80 mM for 7 days. The experiments were conducted in factorial form in a completely randomized design with three replications. The results showed that salinity stress significantly decreased growth parameters (fresh and dry weight of shoot and root), leaf water content (RWC), protein content and increased lipid peroxidation and ion leakage. In addition, the amount of proline, gamma-aminobutyric acid (GABA) and the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPOX) and ascorbate peroxidase (APX) increased under salt stress. Pretreatment with Spm improved growth and increased plant resistance against salt stress. Spm by increasing antioxidant activity (SOD, CAT, GPOX, and APX), proline and GABA content reduces oxidative stress, lipid peroxidation, ion leakage and finally, increased growth parameters. Therefore, Spm pretreatment is suggested as an efficient strategy to improve plant growth and raise pumpkin tolerance against salt stress.

In order to investigate the effects of using some growth biostimulants in low irrigation in pomegranate (Ghojagh cultivar), a two-year experiment, from March 2018, in a split plots design and in randomized complete blocks array, was carried out in Qom. The main plots included irrigation based on the irrigation SWAT model and 70 percent of it. The sub-plots were1-control (based on soil test), 2-treatment 1+ foliar application of amino acid in concentration of 5 gram.lit-1, 3-treatment 1+ soil-use of humic acid, 4-treatment 1+ foliar application of folvic acid in concentration of 5 gram.lit-1 5- treatment1+ foliar application of seaweed extract in concentration of 5 gram.lit-1 6- consumption of Mycorrhiza in the form of hole-layed and 7- combination of treatments 2, 3, 5 and 6. The results of the experiment showed that the effects of irrigation treatment on the characteristics such as number of fruits per tree, acidity of fruit juice and all nutrients, except nitrogen, were significant. Also, the effects of growth biostimulants on all the studied characteristics such as yield and number of fruits per tree, acidity of fruit juice, percentage of soluble solids and concentration of all macro and micro elements were significant. The highest fruit yield.tree-1, hectare-1 and the number of fruits.tree-1 were obtained using seaweed and 70% irrigation in the first year of the experiment with 29.2 kg and 29200 kg.ha-1 and 96.66, respectively.In total, the results showed that reducing the amount of irrigation water calculated based on the water requirement of pomegranate up to 30%, did not have a significant effect on fruit yield and some characteristics of pomegranate. The consumption of biostimulants influenced the yield and some characteristics of pomegranate.

In order to investigate the effect of humic acid on the physiological characteristics, antioxidant activity and yield of Cape gooseberry (Physalis peruviana L.) under deficit irrigation conditions, a split plot experiment based on randomized complete block design with three replications was conducted in 2021. Treatments consisted of the arrangement of three levels of irrigation (starting irrigation at 100, 80 and 60% ETc (crop evapotranspiration)) and three levels of humic acid (0, 1.5 and 3 kg ha-1). The results showed that deficit irrigation significantly reduced fruit yield. The soil application of humic acid significantly increased leaf relative water content, antioxidant capacity, fruit yield, and decreased leaf electrolyte leakage under normal and deficit irrigation. The highest value of total phenol (18.1 mg gFW-1), flavonoid (0.47 mg gFW-1), antioxidant activity (90.06 %), proline (5.91 mg gFW-1) and catalase (0.81 μmol H2O2 g-1 FW min-1) and peroxidase (1.92 units g-1 FW min-1) enzymes activity were obtained with 3 kg ha-1 soil application of humic acid under deficit irrigation 60% ETc. The maximum fruit yield (4793.3 kg ha-1) was observed in plants treated with 3 kg ha-1 humic acid under 100% ETc irrigation. According to these results, the application of 3 kg ha-1 humic acid is suggested to improve the antioxidant capacity and fruit yield of Cape gooseberry under normal and deficit irrigation conditions.

Extreme heat-stress events have become more frequent due to climate change often with devastating effects on rice production. Accumulation and translocation of nitrogen (N) in rice organs is an important process that determines rice yield and quality, which will usually change under the influence of environmental stresses including heat. In this order, the research was conducted with the aim of the effect of heat stress induced by planting date and its effect on seed nitrogen sources in rice cultivars (Oryza sativa L.). An experiment was carried out with two factors of planting date and cultivar in split plots arrangement based on randomized complete blocks design in three replications in 2017 and 2018 in the south of Khuzestan province. In order to face high temperatures (heat stress) in field conditions, three planting dates of May 15, June 5, and June 25 respectively with long-term average temperatures of 36.8, 33.4, and 34.2 0C were selected as the main plots. The sowing date with favorable temperature conditions (33.40C) was considered as control and the early sowing date was considered as heat stress (36.80C) so the flowering and seed filling period was faced with heat stress (39.10C). At each planting date, 7 rice cultivars including Anbouri, Champa, Daniyal, Gerdeh, Hamr, and Hoveyzeh (native cultivars) and N22 (International cultivar) were cultivated as sub-plots. The results showed that in all three planting dates in all cultivars, the highest amounts of remobilized nitrogen and nitrogen remobilization efficiency from leaves to grain were obtained in plant leaves. Hoveyzeh and Hamer cultivars, while having higher amounts of direct nitrogen uptake, had higher efficiency and a higher contribution of nitrogen remobilization. In the first planting date, Hamr and Hoveyzeh cultivars clearly had a significant advantage in leaf nitrogen remobilization and total nitrogen remobilization compared to Champa and Anbouri cultivars. However, the contribution of nitrogen remobilization in these cultivars showed a significant decrease compared to Champa and Anbouri cultivars. Among the studied cultivars, the highest nitrogen harvest index was obtained in modified and dwarf Daniyal cultivars with an average of 67.59%, followed by Hoveyzeh and N22 cultivars. In general, it can be concluded that due to heat stress during the reproductive period of the plant, the lowest amounts of nitrogen were absorbed in the grain and also the lowest values ​​of nitrogen remobilization and the contribution of remobilization nitrogen in grain nitrogen supply were obtained. Also, heat-tolerant cultivars (Howeizah, Hamar, and Daniyal) had the highest nitrogen transfer efficiency in all three planting dates and these cultivars can be used in breeding programs.

Tea (Camellia sinensis L. O. Kuntze) belongs to the Theaceae family and as one of the most important economic plants in the world, it has many medicinal properties and is consumed as a fun drink. Induction of polyploidy using mutagenic chemicals is one of the methods of breeding medicinal plants in order to increase the ability to produce secondary metabolites. In order to investigate the effect of colchicine treatment on the induction of polyploidy and to compare the changes of different traits in tetraploid and diploid plants (control) of Kashef cultivar, an experiment was carried out as a factorial in the form of a completely randomized design with two factors contains different concentrations of colchicine (0, 0.2, 0.5 and 1%) and duration times (3 and 6 consecutive days) with three replications. Morphological, microscopic and chromosomal counts were used to determine the ploidy level. The number of chromosomes in diploid and tetraploid plants was recorded as 30 (2n=2x=30) and 60 (2n=4x=60), respectively. The results showed that the concentration of 0.5 % colchicine in a period of 6 consecutive days with an efficiency of 12.82 % is the most suitable treatment for the production of tetraploid plants. Induction of polyploidy caused significant changes in the leaf size, chlorophyll and carotenoid contents and increased phytochemical compounds such as polyphenol, caffeine and antioxidant activity in tetraploid shoots compared to diploid. Based on the results of this experiment, increasing the ploidy level caused an increase in antioxidant compounds and some phytochemical compounds in tea medical plant.

Amending biochar alone or with microbial inoculation, as a soil amendment, helps to reduce the toxicity of heavy metals in contaminated agricultural soils. On the other hand, the interaction of inoculation with microorganisms and the application of biochar on the absorption of lead and zinc and the growth and yield of plants are somewhat unclear. The objective of this greenhouse experiment was to explore the influences of the application of biochars (obtained from peanut shells and carrot pulps) and conidial suspension of Trichoderma fungi (Trichoderma harzianum Rifai-T22) on seedling growth and some physiological characteristics of sainfoin grown in the soil polluted with heavy metals Pb and Zn. The application of biochars and inoculation with Trichoderma fungus improved the growth parameters of sainfoin seedlings such as root length, plant height, fresh and dry leaf weight. Also, the synergy of these treatments caused an increase in the total protein content, the soluble sugars, the total flavonoids in roots and leaves, catalase and peroxidase activity and also the rate of seedling germination compared to the control treatment (no use of biochar and conidial suspension). Overall, the application of biochar and Trichoderma in soils contaminated with heavy metals caused enhanced growth of sainfoin seedlings by improving some physiological parameters in the leaves, increasing root growth, alleviating the oxidative stress-induced damage and thus possible improvement in water and nutrient uptake.

In order to investigate the effect of seed priming with chitosan on germination characteristics and activity of antioxidant enzymes in rice seedlings under salinity stress, a factorial experiment was conducted in a completely randomized design with four replications at the Mohaghegh Ardabil University in 2022. Treatments included four salinity levels (0, 50, 100 and 150 mM) and four chitosan levels (0, 0.25, 0.50 and 0.75% by weight-volume, all of which were dissolved in 1% acetic acid). The results showed that salinity stress reduced germination rate (GR), germination percentage (GP), radicle, pedicel and seedling length (RL, PL and SL), radicle and pedicel fresh and dry weight (RFW, PFW, RDW and PDW), seedling length and weight vigor index (SLVI and SWVI). But, seed pretreatment with chitosan reduced the effect of salinity and improved these traits. However, the comparison of the means showed that there was a significant difference between the levels of chitosan, so that the highest number of traits obtained from the use of chitosan was 0.75%, and the lowest was obtained without chitosan. Salinity increased the Mean Germination Time (MGT), so that the highest was observed at (0.366 day) salinity of 150 mM and the lowest at 0.75% chitosan (0.101 day) and the highest allometry coefficient (AC) (0.452) was observed in priming with chitosan 25% and salinity of 150 mM. The activity of Catalase (CAT), Peroxidase (POX) and superoxide dismiotase (SOD) in priming with chitosan 0.75% and salinity of 150 mM were the application 40, 35 and 31% higher than the control (distilled water) and without salinity, respectively. Salinity also reduces the activity of the enzyme amylase. Thus, the lowest amylase (6.400 mg g-1 FW min-1) was obtained in the control (distilled water) and salinity of 150 mM. The results showed that chitosan by stimulating antioxidant enzymes and neutralizing free radicals can reduce the harmful effects of salinity stress on some traits in rice seedlings and improve seedling growth.

Priming is the exposure of organisms or cells to a small amount of physically or chemically damaging agents that prepare the organism for subsequent stress exposure through an enhanced response. Accordingly, in this study, the effect of pretreatment of four different LED lights including red LED light, red LED light (70%) + blue light (30%), blue LED light and white LED light in comparison with greenhouse light on two green and purple genotypes of sweet basil was studied under control and salinity stress with a concentration of 150 mmol NaCl. For research, seeds of two genotypes of green and purple sweet basil were planted in pots containing sandy loam soil. After 50 days, 48 pots were transferred to a chamber containing LED lamps and 12 pots were kept in the greenhouse. After 2 weeks, the pots were transferred from the chamber containing LED lamps to the greenhouse and salinity treatment was applied for 2 weeks. The results showed that 150 mM NaCl treatment reduced the fresh and dry weight of shoot and chlorophyll a and increased the amount of hydrogen peroxide, catalase activity and total phenolic compounds in both genotypes under greenhouse light conditions. In light control conditions in both genotypes, red + blue LED light increased the fresh and dry weight of aerial parts, chlorophyll a and total phenolic compounds and decreased the content of hydrogen peroxide compared to other lights. In saline conditions, the results showed that pretreatment with red + blue LED light in green genotype and red LED in purple genotype increased shoot fresh weight (65% and 52%, respectively) and shoot dry weight (2 and 73%, respectively), chlorophyll a (98% and 58%, respectively), total phenolic compounds (2 times and 20%, respectively) and the activity of antioxidant enzymes and reduction of hydrogen peroxide content (33% and 72%, respectively) compared to plants not pre-treated with these lights. According to the results, the use of LED pretreatment (red + blue LED light in green genotype and red LED in purple genotype) by strengthening support mechanisms such as reducing membrane lipid peroxidation, increasing the activity of antioxidant enzymes, phenolic compounds and photosynthetic pigments have played an important role in improving the condition of basil in both control and salinity conditions.

In order to investigate the effect of plant density on yield and physiological traits of two cultivars of lentils Kimia and Bilesvar, a factorial split plot experiment with a randomized complete block design with three replications was conducted at Khodabandeh Dryland Research Station in Zanjan in two cropping years 2015 to 2017. Three spacing between rows (15, 20 and 25 cm) and six levels of seed density (150, 175, 200, 225, 250 and 275 seeds per m2) were considered. Between the two years of the experiment, a significant difference was observed in terms of total yield at the 1%. In terms of the parameters of leaf temperature, stomatal conductance, substomatal CO2, photosynthesis rate at 5% and total yield at 1%, significant difference was observed between planting intervals. Significant difference was observed between the studied genotypes in terms of leaf temperature and total yield at 1% and water use efficiency at 5%. As the distance between the rows increased, the leaf temperature increased, so that the highest and lowest temperatures were observed at the distance between the rows of 25 and 15 cm, respectively. The highest and lowest stomatal conductance were obtained at the distance between rows of 15 and 25 cm, respectively. Increasing the row spacing from 15 to 25 cm decreased the total yield. At 15 cm row spacing, the lowest leaf temperature and the highest stomatal conductance, substomatal CO2 and photosynthesis rate were observed, and the highest yield was also obtained in this row distance; Therefore, by choosing this row distance, in terms of these physiological traits, the farm will be in more favorable condition and eventually a higher yield will be obtained. The highest and lowest yields were related to seed densities of 225 and 150, respectively. Of course, the density of 225 was not significantly different from the density of 200. Therefore, for the cultivation of dry lentils, the best density was 200 seeds per square meter and the best row spacing for planting was 15 cm.

This study was conducted to investigate the potential of copper (Cu) absorption and accumulation and the effects of its contamination on the growth and mineral nutrient content of Artemisia absinthium and Silybum marianum under greenhouse conditions. This was done under factorial experiment based on a completely randomized design and Copper sulfate (CuSO4.5H2O) solution was added to the pots with three replicates at 0 (control), 100 and 200 mg/kg and then seeds of two plant species were sown. Plant harvesting was done after two months when growth was completed and then plant growth characteristics and mineral elements (Ca, Mg, K, P, Fe, Zn, Mn, and Cu) were measured for roots and shoots. The results showed that there was no effect of copper sulfate stress on roots and shoots of A. absinthium while shoot biomass and root volume, area and length of S. marianum were significantly reduced. The Cu accumulation in roots of both plant species and in shoots of S. marianum significantly increased by increasing the copper sulfate in soil. The highest level of Cu accumulation was found in shoots and roots of S. marianum with 53.50 and 168.72 mg/kg dry matter, respectively. A transfer factor less than one for both plants indicated their ability to copper accumulation in the roots. Potassium content in the shoot of S. marianum was significantly greater than that in A. absinthium at treatment of 200 mg/kg. There was no effect of copper sulfate stress on the micronutrients content of A. absinthium while it caused a significant decrease in Mn and Zn in shoot and root of S. marianum, respectively, and a significant increase in Fe in the shoot of S. marianum.

In order to investigate the effect of drought stress on some morphological, physiological, and biochemical traits of the medicinal plant Teucrium stocksianum Boiss, an experiment was conducted in the form of a completely randomized design by 5 rounds of irrigation of 0, 4, 6, 8 and 10 days and in four replications. The results showed that severe drought stress caused a significant decrease (P < 0.05) in leaf length and width, plant height and width, root length, plant width, the diameter of main and secondary stems, fresh weight of shoots and roots, and dry weight of shoot and root, relative humidity content, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids. The highest amount of ion leakage, proline, catalase, polyphenol oxidase, malondialdehyde, flavonoid, and anthocyanin were observed in severe drought treatment. In general, by using defense mechanisms such as reduction of morphological traits, rapid accumulation of organic substances regulating osmosis, and increasing the activity of antioxidant enzymes, the medicinal plant Teucrium stocksianum Boiss showed a suitable response to drought stress and absorbed nutrients by spending minimal energy and the growth continues.

In order to investigate the effect of brassinosteroid foliar application on the growth characteristics and content of sodium and potassium ions of summer savory (Satureja hortensis L.) under salt stress, a factorial experiment was conducted based on randomized complete block design with three replications in the greenhouse of Payam Noor University in Lorestan in 2020. The factors were salinity stress at three levels (0, 40 and 80 mmol/L NaCl) and foliar sprays of brassinosteroid at three levels (0, 0.5 and 2 μmol/L). The largest mean values of plant height (32.56 cm), root length (22.02 cm), shoot fresh weight (5.89 g/plant), shoot dry weight (2 g /plant), root dry weight (0.87 g/plant), and potassium content in plant shoot (16.39 mg/g dry matter) were observed under control conditions (without salinity). These traits declined by 32, 21, 19, 17, 31, 23 and 79%, respectively, under salinity conditions (80 mmol /L NaCl). However, spray of brassinosteroid, especially at 2 μmol /L, increased mean plant height (30.46 cm), root length (21.7 cm), fresh and dry weights of shoot (5.95 and 2.06 g/plant, respectively), and potassium content of aerial organs (10.63 mg/ g dry matter).The interaction effects of the salinity and hormone spray indicated that increases in salinity level significantly improved sodium content of plants (sodium content was 10.93 mg/g dry matter in the treatment of applying 80 μmol/L NaCl and no hormone spray). This led to a drastic reduction in the potassium/sodium ratio (the mean value of this trait was 0.2 in the treatment of applying 80 mmol/L NaCl without hormone spray); however, spray of brassinosteroid somewhat reduced sodium absorption (the sodium content in the treatment of applying 80 mmol/L NaCl and 2 μmol/L of the hormone was 6.56 mg/g dry matter). In general, salinity decreased the studied plant growth traits by disrupting potassium absorption and strongly reducing plant potassium /sodium ratio, but brassinosteroid spray improved the fresh and dry weight of summer savory plants.

Salinity is one of the environmental stresses that has a negative effect on the growth process and its causes oxidative stress in plants. A factorial experiment was carried out in the form of a completely randomized design, in order to investigate the effect of SNP on reducing the oxidative stress of Salicornia Persica, under salt stress, with three repetitions. In this research, the effect of two levels of SNP (0 and 0.2 mM), three levels of salinity (0, 200, 500 microgram/ml sodium chloride) and three stages of harvest (1, 7 and 14 days) were evaluated. The results showed that the dry weight of aerial parts decreased with increasing salinity. The exception was an increase in salinity of 200. The positive effect of SNP was observed in salinity of 200 and 500. The content of relative water decreased with increasing salinity concentration and SNP caused the content of relative water increased at three levels of salinity. The amount of anthocyanin decreased with increasing salinity and SNP caused an increase in the amount of anthocyanin. Malondialdehyde increased with increasing salinity, and the application of SNP caused its decrease. The amount of phenol decreased with increasing salinity and SNP did not have a significant effect on phenol. However, the amount of flavonoids increased at 200 salinity compared to control and it’s decreased at 500 salinity. Salinity stress caused an increase in the amount of sodium and the application of SNP caused it’s to decrease. The amount of potassium increased at 200 and 500 salinity. The treatment of SNP caused an increase in the amount of potassium at 0 and 500 salinity. In general, it can be concluded that the treatment of SNP can increase Salicornia Persica Salinity tolerance.

Growth promoting bacteria can support host plants against water stress as the most common abiotic stress, especially in arid and semi-arid regions. Peppermint is one of the valuable medicinal plants that can lose yield under water stress conditions. To end this, a factorial greenhouse experiment as randomized complete blocks with three replications was conducted. Treatments included: inoculation and non-inoculation of the Peribacillus simplex 54-1 bacterium on peppermint seedlings and three rates of watering: normal, moderate water stress with stopping watering 10 days before harvesting and severe water stress with stopping watering 20 days before harvesting. The results showed that P. simplex inoculation could increase the fresh and dry yield of the peppermint by 59% and 47%, respectively, in normal watering, as well as by 74% and 58% in moderate water stress and by 64% and 39% in severe water stress. The dry weight of the root was 84% increased under normal watering conditions and averagely 42% increased under water stress conditions in respect to their controls. Bacterium inoculation was able to decrease the production of malondialdehyde as an index of oxidative stress by 2.26 and 4.18 times in moderate and severe stress, respectively, in respect to non-inoculation conditions. Improving the peppermint antioxidant system by increasing the rate of polyphenol oxidase and catalase could be among the possible reasons for this situation. Therefore, this bacterium can be used as a suitable candidate in the preparation of biological fertilizer to deal with water stress in peppermint and increase its production.

In order to study the effects of the application of two-plant growth regulators/proline on some physiological characteristics in fennel under water-deficit stress conditions, an experiment was conducted as a split-plot based on a randomized complete block design with three replications at the research farm, agricultural faculty of Azarbaijan Shahid Madani University, Tabriz-Iran, in 2019. Factors were three irrigation regimes (irrigation at the field capacity (I1), irrigation after depleting 65 (I2) and 85% (I3) of the available water capacity) as the main plot and four foliar spraying (control, exogenous application of methyl jasmonate, uniconazole and proline + triton X-100) as a subplot. Results indicated that the minimum relative water content, membrane stability index, chlorophyll a, b, total (chl.), carotenoids and maximum proline, total soluble sugars, and malondialdehyde contents in leaves were obtained from severe water-deficit stress conditions. Maximum membrane stability index, chlorophyll a, total (chl.), carotenoids, and total soluble sugars were related to plant growth regulator application, especially methyl jasmonate. Interaction effects revealed that physiological growth characteristics were significantly reduced in the control treatment (except for proline and total soluble sugars) compared to foliar spraying treatments by increasing water-deficit stress conditions in the soil. The spraying with methyl jasmonate had a better effect on reducing the effects of water deficit stress on the physiological characteristics of the fennel by regulating of internal reactions and induction of antioxidant defenses. Therefore, methyl jasmonate can be used in water-deficit stress conditions in arid and semi-arid areas and reduce its harmful effects on the fennel plants.

Salinity is one of the most important non-biological stresses that has an adverse effect on the growth and production of crops. Chickpea (Cicer arietinum L.) is sensitive to salt stress. This study was performed to select the salt tolerance genotypes of chickpea. For this purpose, 72 genotypes were screened for dSm-112 salinity tolerance. This study was performed in a completely randomized design with three replications as hydroponic culture. Among the studied genotypes, 53 genotypes had a survival of more than 75%, and no genotype had a survival of less than 25%. The highest mean content of soluble carbohydrates, total phenol, proline, osmotic potential, inhibition of free radical activity of DPPH and relative water content were observed in genotypes with a survival range of 100-76%. The mean malondialdehyde content was highest in genotypes with a survival range of 50-26%. The results of cluster analysis showed the relative superiority of the second group genotypes including MCC1037, MCC1212, MCC1286, MCC1138, MCC1278, MCC1129, MCC1140, MCC1234, MCC1299, MCC1289, MCC1041, MCC1132, MCC1276, MCC1211, MCC1211 and MCC1010 in most of the studied traits. Chickpea genotypes appear to use a variety of mechanisms to tolerate salinity, which helps to replace more salinity-tolerant genotypes in tolerant chickpea.

Drought is one of the most important abiotic stresses that affects the growth and development of plants. Adaptation of the plants to abiotic stresses causes changes in the expression of a large number of defense genes and their regulators, including transcription factors. MYB proteins are a large family of transcription factors that are of particular importance in regulating developmental processes and defense responses in plants. In this study, the expression level of eight MYB transcription factors from bread wheat in Tajen and Zagros cultivars was investigated in response to drought stress. RT-PCR analysis showed that almost all genes of the MYB family, including TC282418, TaMYB80, PTTa00740, TaMYB33, TaMYBR3, were expressed with 2.4, 3.2, 7.1, 6.1, and 6.6 respectively, had an increased expression compared to the control under severe stress in the Zagros genotype that was examined in this research. On the other hand, the Zagros variety, which is one of the drought stress-tolerant varieties, had a higher expression increase than the Tajen variety for all the studied genes.