Agriculture and horticulture
niloufar Rezaei; Fatemeh Sefidkon; hassan ali naghdibadi
Abstract
Background and Objective: The cultivation of medicinal plants, including savory (Satureja), is increasing worldwide. Savory, containing thymol and carvacrol in its essential oil, holds significant importance. This study aims to investigate the effects of planting density and soil fertility on the physiological ...
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Background and Objective: The cultivation of medicinal plants, including savory (Satureja), is increasing worldwide. Savory, containing thymol and carvacrol in its essential oil, holds significant importance. This study aims to investigate the effects of planting density and soil fertility on the physiological traits and antioxidant enzyme activities of savory under rainfed conditions. Considering the importance of these factors in enhancing plant resistance to stress, this research was conducted to determine the optimal planting density and soil fertility for boosting antioxidant activities and promoting the sustainable development of savory.Methodology: This study was conducted as a field experiment at the Hamand Absard Research Station in Damavand during the 2017–2018 and 2018–2019 growing seasons. The experiment was arranged in a split-plot design within a randomized complete block design (RCBD) with two factors. The main factor consisted of three fertilizer levels: (1) control (no fertilizer), (2) decomposed cattle manure (30 tons per hectare), and (3) straw enriched with ammonium sulfate (10 tons per hectare). The sub-factor included three planting densities: 2.67, 4, and 8 plants per square meter. Planting was performed using standard savory seeds. Land preparation involved plowing, disking, and leveling. Fertilizers were applied according to the treatments before planting. Irrigation was limited to rainfed conditions only. Leaf samples were collected at the full flowering stage. The measured physiological traits included relative leaf water content, total chlorophyll, proline content, electrolyte leakage, ion leakage, malondialdehyde content, and antioxidant enzyme activities (catalase, peroxidase, and superoxide dismutase). Samples were analyzed in the laboratory after harvest to evaluate the effects of treatments on the studied parameters. Data was analyzed using SAS software, and mean comparisons were performed using Duncan’s multiple range test at a 5% significance level.Results: This study demonstrated that planting density and organic fertilizer treatments significantly influenced the physiological traits and antioxidant defense responses of Satureja spicigera under rainfed conditions. The highest relative water content (87.67%) and the lowest electrolyte leakage (47.19%) were recorded in the treatment with cow manure and a low planting density of 2.67 plants per square meter, indicating improved water status and membrane stability. In contrast, increasing planting density reduced chlorophyll content and relative water content, while levels of proline, electrolyte leakage (ELI), and malondialdehyde (MDA) increased, reflecting greater stress intensity under high-density conditions. The application of cow manure and ammonium sulfate-enriched straw improved physiological performance and significantly reduced oxidative stress markers. These treatments promoted better osmotic regulation and membrane protection, contributing to greater stress tolerance. Interestingly, the highest activities of antioxidant enzymes, catalase, peroxidase, and superoxide dismutase were observed in the unfertilized control under high-density planting. This suggests that the plant naturally boosts its enzymatic antioxidant defenses under more stressful conditions, particularly when nutrients are limited. In conclusion, the results highlight that integrating organic fertilization with optimal planting density can enhance drought resilience by maintaining physiological stability and reducing oxidative damage. These practices not only support the sustainable cultivation of Satureja spicigera in water-limited environments but also improve the plant’s overall functional and medicinal quality.Conclusion: The results of this study show that savory (Satureja spicigera) has a good ability to grow and develop under rainfed conditions and demonstrates significant capacity to enhance its antioxidant activity. The combined use of organic fertilizers, especially cow manure, along with an appropriate planting density, is practical in improving physiological traits, increasing resistance to environmental stresses, and strengthening the plant’s enzymatic defense system. Implementing these findings can be valuable in enhancing productivity, ecological sustainability, and food security in areas with limited water resources.
Agriculture and horticulture
Nasrin Biyabani; Vahid Abdossi; Marziyeh Ghanbari Jahromi
Abstract
Background and objectives: Salinity stress is one of the most significant abiotic stresses that impede agricultural production. It is often accompanied by oxidative stress due to the generation of reactive oxygen species (ROS). Mitigating the effects of environmental stress on plants through the use ...
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Background and objectives: Salinity stress is one of the most significant abiotic stresses that impede agricultural production. It is often accompanied by oxidative stress due to the generation of reactive oxygen species (ROS). Mitigating the effects of environmental stress on plants through the use of growth-promoting compounds is of particular importance. In this context, silicon sources, such as potassium silicate, play a critical role in modulating salinity stress in plants. By enhancing plant resistance to salt stress, potassium silicate can contribute to improved growth and performance in areas with saline soils. These compounds promote cellular ion balance under adverse conditions and improve water uptake and retention in plants, thereby reducing ion leakage and the detrimental effects of salinity stress.Methodology: The present study aimed to investigate the effect of potassium silicate on the growth and physiological and biochemical characteristics of goldenrod in a factorial design based on a completely randomized design with the factor of salinity stress at three levels (0, 60, and 120 mM) and foliar application of potassium silicate at three levels (0, 50, and 100 mg/l) under greenhouse conditions. Foliar application was carried out three times at 15-day intervals. The first foliar application was performed at the 4-leaf stage. After the second foliar application, salinity stress was induced by applying 200 milliliters of sodium chloride solution to each pot for 40 days. To prevent salt accumulation in the pots, all pots were rinsed with non-saline water after every 4 irrigations with saline water. The morphological variables investigated include wet and dry weight of shoots and roots and plant height and other traits including plant pigments (chlorophyll a, b and total), relative leaf water content, ion leakage rate, proline, sodium and potassium absorption rate of roots and it was the aerial parts that were measured in the middle of the golden grass flowering period.Results: Salinity stress caused yield reduction, and potassium silicate moderated the negative effects of salinity stress and improved plant growth conditions. The evaluations showed that the salinity of 120 mM caused a decrease in the fresh weight of shoot (28%), dry weight of shoot (29%), fresh weight of root (38%), dry weight of root (37%), total chlorophyll (40%), the relative content of leaf water (17%), root potassium (14%) and leaf potassium (16%) and increased ion leakage (23%), proline (13%), root sodium (256%), sodium leaves (325%). Potassium silicate, especially 100 mg/l, moderated salinity stress by increasing plant weight, chlorophyll, leaf water, and potassium content in leaves and roots and reducing sodium accumulation in leaves and roots and ion leakage.Conclusion: The general results of the research showed that increasing the intensity of salinity stress had negative effects on the growth and functional characteristics of golden grass and potassium silicate in the volume of 50 to 100 mM caused the adjustment of salinity stress by increasing the quantitative and qualitative performance (biochemical and phytochemical) of golden grass. Therefore, to cultivate the golden grass plant, it should be noted that the water or soil used does not contain salts such as sodium and chlorine, or soil conditioners or growth stimulants should be used for the production and cultivation of this plant.
Agriculture and horticulture
Hayder Mohammed Khudhair Al jazea; Bahram Abedy; Seyyed Hossein nemati
Abstract
Background and objectives: Mentha longifolia L. belongs to the Mentha genus and the mint family (Lamiaceae). This plant naturally grows in moist environments, such as riverbanks, and its cultivation in fields and greenhouses requires high-quality water. Water and soil salinity are among the most critical ...
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Background and objectives: Mentha longifolia L. belongs to the Mentha genus and the mint family (Lamiaceae). This plant naturally grows in moist environments, such as riverbanks, and its cultivation in fields and greenhouses requires high-quality water. Water and soil salinity are among the most critical agricultural challenges in hot and arid regions. In such areas, soil salinity and water scarcity are the primary factors that reduce the growth and yield of crops. Identifying and utilizing ecotypes and cultivars resistant to salinity stress can help prevent production losses. This study aims to investigate the effects of different water salinity levels on the morphological and physiological traits of three wild brookmint ecotypes to identify the most salt-tolerant ecotype.Materials and Methods: This study was conducted using a completely randomized design in factorial form with two factors at Ferdowsi University of Mashhad. The first factor was ecotype, with three levels (E1: South Khorasan, E2: Lorestan, E3: Fars), and the second factor was salinity stress, with four levels (0, 75, 100, and 150 mM sodium chloride). Salt stress treatments were applied beginning at the four-leaf stage, and at the eight-leaf stage, morphological traits were measured, including plant height, number of leaves, number of flowers, flower length, fresh and dry leaf weights, and fresh and dry root weights. Physiological traits assessed included chlorophyll a, chlorophyll b, total carotenoids, electrolyte leakage, total phenol content, total flavonoid content, proline content, and total carbohydrate content. Data was analyzed using Minitab 19 software.Results: The results showed that the main effects of ecotype and salinity stress and their interaction significantly influenced morphological traits such as plant height, root weight, and root dry weight. The main effects of ecotype and salinity stress on leaf weight and leaf dry weight were also significant. However, the main and interaction effects on traits such as number of leaves, number of flowers, and flower length were not significant. Salinity stress significantly reduced morphological traits in all ecotypes compared to the control, including plant height, leaf weight, dry weight, root weight, and dry weight. Regarding physiological traits, the main effects of ecotype and salinity stress, along with their interaction, significantly affected chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, electrolyte leakage, total flavonoid content, and proline content. The main effects of ecotype and salinity stress on total phenol content were significant, while their effects and interactions on carbohydrate content were not significant. Salinity stress led to a reduction in chlorophyll a, b, total chlorophyll, and carotenoids. Conversely, this stress increased proline content, electrolyte leakage, and the levels of total phenol and flavonoid compounds in the leaves compared to the control.Conclusion: Based on the evaluation of the measured traits in the three wild brookmint ecotypes, it was evident that these ecotypes responded differently to salinity stress. The results indicated that the E1 ecotype (South Khorasan) was superior to the others in terms of the traits studied and exhibited greater tolerance to salinity stress conditions.
Improvement and breeding
Fatemeh Zakerian; Fatemeh Sefidkon; Bohloul Abbaszadeh; Sepide Kalatejari; Masoumeh Layeghhaghighi; Najmeh Hadi
Abstract
Background and objectives: Among the 16 species of Satureja in Iran, 10 are endemic, including S. bachtiarica, S. khuzistanica, S. intermedia, S. sahendica, S. isophylla, S. rechingeri, S. edmondi, S. kallarica, S. atropatana, and S. kermanshahensis. Satureja sahendica Bornm. is a perennial plant with ...
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Background and objectives: Among the 16 species of Satureja in Iran, 10 are endemic, including S. bachtiarica, S. khuzistanica, S. intermedia, S. sahendica, S. isophylla, S. rechingeri, S. edmondi, S. kallarica, S. atropatana, and S. kermanshahensis. Satureja sahendica Bornm. is a perennial plant with essential oil widely used in the pharmaceutical, food, health, and cosmetic industries. Its antiviral properties have also been documented. Drought stress is one of the most significant environmental challenges for plants, leading to reduced water absorption, stomatal conductance, transpiration, and photosynthesis, while also disrupting hormonal balance. Plants adopt various mechanisms to mitigate drought stress, such as increasing osmotic regulators like sugars, proline amino acids, and proteins. Drought conditions typically decrease chlorophyll content while increasing carotenoids. Additionally, oxidative stress intensifies under drought, leading to the accumulation of reactive oxygen species such as catalase, superoxide dismutase, and ascorbate peroxidase in chloroplasts and mitochondria. Mycorrhizal fungi play a crucial role in enhancing root absorption, regulating water movement within host plants, and ultimately improving tissue water uptake and leaf physiology.Methodology: This experiment was conducted using a split-plot design within a randomized complete block design (RCBD) with three replications at the Research Institute of Forests and Rangelands during 2015–2016. The main factor was irrigation treatment, consisting of full irrigation (control), irrigation interruption at the stem stage (resumed at the budding stage), irrigation interruption at the budding stage (no irrigation until the end of the flowering period), and irrigation interruption at the 50% flowering stage (no irrigation until the end of flowering). The secondary factor was biological fertilizer application, which included no biofertilizer (control), inoculation with Glomus intraradices, inoculation with Glomus mosseae, and inoculation with Glomus mosseae + Glomus intraradices. Throughout the growth period, irrigation was maintained at 80–90% of field capacity, and drought treatments were applied based on plant morphology. The biofertilizers contained mycorrhizal fungi (Glomus intraradices and Glomus mosseae) in the form of active fungal structures, including spores, hyphae, and roots. Before transplanting the seedlings, 10 grams of biofertilizer, containing 400 to 500 active fungal units, was applied to each planting hole.Results: The interaction effect of drought stress and mycorrhiza was significant at the 1% probability level for protein, catalase, superoxide dismutase, peroxidase, chlorophyll a, total chlorophyll, proline, polyphenol oxidase, soluble sugars, essential oil percentage, essential oil yield, and flowering shoot yield, while its effect on carotenoid and total phenol was significant at the 5% level. The results indicated that the yield of p-cymene, γ-terpinene, and thymol was significantly influenced at the 1% level by the triple interaction of year, drought stress, and mycorrhiza. Mean comparisons revealed that catalase, superoxide dismutase, chlorophyll b, proline, total phenol, essential oil percentage, and essential oil yield were higher in the second year. Regarding drought stress, the highest flowering shoot yield was observed under full irrigation and moisture stress applied at the full flowering stage. Mycorrhizal treatment comparisons showed that the highest malondialdehyde release occurred in plants without inoculation and those treated with the combination of Glomus intraradices + Glomus mosseae. Essential oil analysis revealed that the highest percentage (2.23%) was obtained in the budding stage treatment with G. mosseae, while the highest essential oil yield (51.78 kg/ha) was recorded under full irrigation with G. intraradices inoculation. The triple interaction (year × drought stress × mycorrhiza) analysis showed that in the first year, the highest thymol yield (74.59%) resulted from full irrigation combined with G. mosseae inoculation.Conclusion: Therefore, it can be concluded that the application of biological fertilizers effectively mitigated the effects of drought stress, leading to an increase in both the essential oil percentage and thymol content.
Agriculture and horticulture
Ahmad Bakhshi; Vahid Abdossi; Marziyeh Ghanbari Jahromi
Abstract
Background and objectives: Water availability is one of the most critical climatic factors influencing plant distribution worldwide. Drought stress, resulting from insufficient water availability, can induce plant morphophysiological, biochemical, and functional changes. Seaweed contains a high percentage ...
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Background and objectives: Water availability is one of the most critical climatic factors influencing plant distribution worldwide. Drought stress, resulting from insufficient water availability, can induce plant morphophysiological, biochemical, and functional changes. Seaweed contains a high percentage of polymer compounds capable of absorbing water molecules and forming a gel-like structure. Additionally, its rich composition of salts and essential minerals fulfills plant nutrient requirements, promotes growth and yield, enhances resistance to environmental stress, improves nutrient uptake from the soil, and boosts antioxidant properties. Tarragon (Artemisia dracunculus L.) is an herb widely used as a flavoring agent in the food industry, with its essential oil playing a key role in canning and perfumery. Because seaweed extract serves as a natural biofertilizer, providing essential nutrients and plant growth hormones while being environmentally friendly, it represents a viable alternative to chemical fertilizers. Moreover, it enhances plant resilience to various environmental stresses and contributes to sustainable food production. This study aims to investigate the effects of seaweed extract on the growth and biochemical characteristics of tarragon under drought stress conditions.Methodology: This study was conducted to investigate the growth, physiological, and biochemical characteristics of the medicinal plant tarragon (Artemisia dracunculus L.) under drought stress at four levels (100%, 80%, 60%, and 40% field capacity) and foliar application of aqueous Sargassum seaweed extract at three concentrations (0 g/L [control], 1 g/L, and 2 g/L). The experiment was carried out in the spring of 2023 in a greenhouse located in Damavand, using a factorial arrangement based on a completely randomized design with three replications. Four-leaf tarragon seedlings were obtained from the training farm of Damavand Technical and Vocational School and transplanted into three-liter pots. After a 10-day establishment period, drought stress was applied for 45 days, with foliar spraying of seaweed extract performed every two weeks, starting simultaneously with the onset of drought stress. Soil moisture levels in the pots were monitored daily by weighing them, and water was added as needed to maintain the target field capacity for each treatment. Plant sampling was conducted one week to 10 days after the completion of treatments, coinciding with the transition from vegetative to reproductive growth. Morphophysiological traits, including fresh and dry biomass, plant height, and the number of secondary branches, were measured. Additionally, biochemical parameters such as proline content, soluble carbohydrates, total phenol and flavonoid content, antioxidant activity, and essential oil yield and percentage were analyzed.Results: The results indicated that under severe drought stress (40% field capacity) and in the absence of seaweed extract application, there was a significant reduction in morphophysiological traits, including plant height, main stem diameter, number of secondary branches, fresh and dry weight of aerial parts, and photosynthetic pigments (chlorophyll a, chlorophyll b, and total chlorophyll). However, the application of seaweed extract mitigated the adverse effects of drought stress on tarragon. Under mild drought stress (60% field capacity) without seaweed extract application, the highest levels of total phenol (82 mg/g gallic acid), total flavonoid (64.33 mg/g quercetin), antioxidant activity (76%), and essential oil yield and percentage were observed. Drought stress also enhanced the activity of antioxidant enzymes, leading to increased synthesis of soluble carbohydrates and proline compared to the control. Among the tested seaweed extract concentrations, the application of 2 g/L had the most significant positive impact on the evaluated traits, further improving plant resilience and biochemical responses under drought-stress conditions.Conclusion: The overall findings of this study indicate that tarragon exhibits limited resistance to drought stress, with a noticeable decline in yield as stress intensity increases. Under drought conditions, the application of seaweed extract, particularly at a concentration of 2 g/L, effectively mitigated the adverse effects of stress by enhancing morphophysiological and phytochemical traits, including total phenol, flavonoid content, and essential oil yield. In most cases, the difference between 2 g/L and 1 g/L of seaweed extract was statistically significant, with 2 g/L demonstrating superior effectiveness. Therefore, the application of 2 g/L seaweed extract is recommended to improve drought tolerance and maintain yield in tarragon under water-limited conditions.
Improvement and breeding
Borzoo Yoosefi; Roya Karamian
Abstract
Background and objectives: Creeping savory is a medicinal and perennial plant that grows in the north and northwest of Iran. The essential oil of this plant has antibiotic properties and is used in herbal medicines, food preparation, and health products. Salinity stress has adverse ...
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Background and objectives: Creeping savory is a medicinal and perennial plant that grows in the north and northwest of Iran. The essential oil of this plant has antibiotic properties and is used in herbal medicines, food preparation, and health products. Salinity stress has adverse effects on photosynthetic processes and plant growth and yield. Salicylic acid protects plants against stress by regulating many physiological and enzymatic processes. So far, not much information has been published about the effect of salicylic acid on the physiological process, morphologically, and yielding traits of creeping savory under salinity stress conditions.Methodology: This factorial experiment was implemented in the greenhouse of the Kermanshah Agricultural and Natural Resources Research Center based on a Completely Randomized Design including four levels of salinity (0-50-100-150 mM) and two levels of salicylic acid (0 and 2 mM). Chlorophyll fluorescence (Fv/Fm) was measured with a Hansatech, UK Pocket PEA device. The chlorophyll index (SPAD) was measured with a SPAD-502Plus device, Minolta, Japan. Leaf proline content and soluble protein were measured based on Bradford method using a Bio Tek PowerWave XS2 Microplatereader, USA. Various morphological and yield traits such as plant height, leaf area (by a Light Box device, ADC, UK), leaf fresh weight, root fresh weight, and shoot fresh weight (g) were measured. Leaf dry weight, root dry weight, and shoot dry weight were weighed after drying the samples at 75°C for 48 hours. Relative water content (RWC) was calculated. Leaf electrical conductivity (µS/cm) was measured with an EC COND 3110, WTW (Germany). Analysis of variance and comparison of means (Dunkan test) were performed using IBM SPSS Statistics (Ver. 26).Results: The highest plant height (92.7 cm), leaf area (0.8 cm2), shoot fresh weight (26.9 g), and shoot dry weight (9.15 g) were obtained at 0 mM NaCl + 2 mM SA. The highest leaf fresh weight (13.5 mg), leaf dry weight (2.5 mg), quantum yield of photosystem II (0.80), and photosynthetic index (37.0) were observed at 50 mM NaCl + 2 mM SA. The highest root fresh weight (27.3 grams), root dry weight (4.3 grams), and the highest relative water content (91.7 percent) were obtained at 0 mM NaCl. The highest proline (12.7 μg/g) was observed at 150 mM NaCl and the highest soluble protein (1.1 mg/g) was observed at 100 mM NaCl + 2 mM SA. The use of 2 mM salicylic acid, under salinity stress conditions, increased plant height (16.4%), leaf area (18.6%), leaf fresh weight (17.3%), shoot fresh weight (35.4%), shoot dry weight (35.8%), relative water content (8.4%) and soluble protein by 41.4%, but decreased proline content (41.4%) and electrical conductivity (49.4%). Applying 2 mM salicylic acid has a significant effect on root fresh weight, maximum quantum yield of photosystem II and chlorophyll index in mild salinity conditions. Also, SA increased leaf dry weight in mild salt stress but decreased it in severe salinity conditions.Conclusion: This research showed that applying salicylic acid under salinity stress causes changes in some morphophysiological, photosynthetic, and biochemical characteristics of creeping savory. Increasing the salinity levels decreased some photosynthetic, physiological, vegetative, and yield traits, but the content of some osmotic regulators, such as proline and protein, was increased. The application of 2 mM salicylic acid improved some of the adverse effects of salinity in creeping savory at different salinity levels, enhancing growth and yield traits in the salicylic acid-treated plants. Applying two mM salicylic acid increases the tolerance of creeping savory against salinity stress by increasing the osmotic protectants and inducing the activity of antioxidant systems. Based on the research results, growing this plant in soils with a salinity of more than 100 mM is not recommended. Also, in the case of planting creeping savory in saline soils (less than 100 mM), to increase plant growth and farmers' income, it is recommended to apply two mM salicylic acid as a foliar spray.
Improvement and breeding
Ghobad Salimi; Fatemeh Javadi
Abstract
Background and purpose: The medicinal plant Ocimum basilicum L. is one of the most important medicinal plants. It is native to tropical regions from Central Africa to Southeast Asia and has antimicrobial, antioxidant, analgesic, and anti-inflammatory properties. Drought stress is one of the most ...
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Background and purpose: The medicinal plant Ocimum basilicum L. is one of the most important medicinal plants. It is native to tropical regions from Central Africa to Southeast Asia and has antimicrobial, antioxidant, analgesic, and anti-inflammatory properties. Drought stress is one of the most important abiotic factors that can severely affect plant growth and yield. This study aimed to investigate the effect of mycorrhizal fungus on some physiological and biochemical properties of the medicinal plant O. basilicum L. under drought stress.Methodology: This experiment was conducted in the research greenhouse of Islamic Azad University, Kermanshah branch in 2022. The experiment was performed as a factorial experiment in a Random completely blocked design with two factors (mycorrhiza fungus) in three levels including control (without inoculation with fungus), G. etunicatum and G. mosseae, water drought stress at three levels (without stress, 75 and 50% of field capacity) were performed in four replications. The traits measured in the experiment include, the number of leaves, relative water content, ion leakage, photosynthetic pigments, proline, carbohydrate, antioxidant activity, phenol content and clonization percentage.Results: The results of analysis of variance analysis showed that the effect of mycorrhizal fungus on all the traits measured in the experiment was significant, and also, the effect of drought stress on all the investigated traits was significant except for the amount of phenol and total chlorophyll. The interaction effect of two factors, mycorrhizal fungus and different levels of drought stress, on the characteristics of ion leakage and carotenoid content was significant. Mean comparisons of data showed that the highest number of leaves (70.5) was observed in the treatment of G. mosseae fungus, and the lowest number of leaves (58) was in the treatment without fungus. The highest relative water content of leaves (79.059%) was in non-stress conditions, which had a significant difference with the stress conditions of 75 and 50% of crop capacity. The highest electrolyte leakage percentage (33.02%) in the stress condition was 50% of the field capacity in the control treatment, which was not significantly different in the same condition as the G. etunicatum fungus treatment. Inoculation with mycorrhizal fungus increased the content of total chlorophyll so that the highest amount of total chlorophyll (0.96 mg/g of fresh weight) was obtained in the treatment of G. mosseae, which was not significantly different from G. etunicatum and also inoculation with mycorrhizal fungi increased the content of chlorophyll a and b by 91.8%. Inoculation with mycorrhizal fungus increased the proline content by 25.33%, too. The highest antioxidant activity (21.13%) was obtained in treating G. mosseaefungus. The lowest amount of essential oil was observed in the 50% of the field capacity treatment, 25.96% less than the control treatment. Drought stress decreased the percentage of root colonization in G. mosseae by 55.77% and in G. etunicatum by 57.93%.Conclusion: Mycorrhizal fungus improved the morphological and physiological characteristics in green basil plant.symbiosis with G. mosseae fungus under drought stress conditions with increasing proline and antioxidant activity, improved physiological traits and resistance to drought stress in green basil plant.
Agriculture and horticulture
F. Beheshti Qolezo; M. Moghaddam; L. Samiei
Abstract
Background and objectives: Maintaining medicinal plants' quality and effective compounds is a fundamental challenge. Salvia L. has antioxidant, anti-inflammatory, and antimicrobial properties and is a rich source of biological compounds that destroy free radicals. Salvia ...
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Background and objectives: Maintaining medicinal plants' quality and effective compounds is a fundamental challenge. Salvia L. has antioxidant, anti-inflammatory, and antimicrobial properties and is a rich source of biological compounds that destroy free radicals. Salvia virgate Jacq. has several biological activities and is used to treat wounds and various skin diseases and prevent blood cancer. Cadmium is one of the most toxic heavy metals due to its long biological half-life, significant mobility in soil, and capacity to be absorbed by plants. Cadmium's negative effects on plant growth, and physiological and biochemical activities reduce plant quality and performance. Sodium nitroprusside is involved in biological processes and responds to various stresses by releasing nitric oxide (NO).
Methodology: To investigate the effect of different levels of sodium nitroprusside on improving the response of salvia virgata to cadmium stress under in vitro conditions, an experiment was conducted in the Research Institute of Plant Sciences of the Ferdowsi University of Mashhad with a factorial design based on a completely randomized design with four replications. The studied factors included different levels of cadmium (0 (control), 25, 50, and 100 µM) and sodium nitroprusside (0 (control), 15, and 30 µM). Murashig and Skoog culture media were used for seed cultivation. In this experiment, different amounts of cadmium nitrate were added to the culture medium before adjusting the pH. Sodium nitroprusside was added to the medium after autoclaving and a sub-laminar filter due to its sensitivity to high temperatures. At first, the seeds were sterilized with 70% alcohol and 2% sodium hypochlorite; then, they were planted in a culture medium. After three months of growth, the seedlings were removed from the culture medium. Growth traits include the fresh and dry weight of the aerial part, root, and whole seedling, and physiological and biochemical traits including photosynthetic pigments (measurement of chlorophyll a, chlorophyll b, carotenoid, total chlorophyll, and total photosynthetic pigment), flavonoid, total phenol, carbohydrate, proline, protein, and antioxidant activity were measured. The data obtained from this research were analyzed by Minitab software. The mean comparisons were done by the Bonferroni test at the five percent probability level.
Results: According to the results of the analysis of variance of the data, the interaction effect of cadmium and nitroprusside on seedling fresh weight, chlorophyll a, chlorophyll b, carotenoid, total photosynthetic pigments, total phenol, carbohydrate and proline at the probability level of one percent and seedling dry weight, total chlorophyll, flavonoid, and protein were significant at the five percent probability level. The interaction effect of treatments on antioxidant activity was not significant, but their simple effects were significant. The results of the mean comparison of the data indicated that cadmium stress decreased the fresh and dry weight of seedlings, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and total photosynthetic pigments in S. virgata, and the application of sodium nitroprusside led to the improvement of these traits; so that the application of 30 μM sodium nitroprusside under cadmium stress with a 50 μM concentration showed the highest fresh and dry weight of seedlings and the proline content, and the application of 15 μM sodium nitroprusside under cadmium stress with a 25 μM concentration showed the highest amount of photosynthetic pigments. Also, this research indicated that cadmium stress increased antioxidant activity, total flavonoid, total phenol, soluble carbohydrate, proline, and protein in the S. virgata plant. However, sodium nitroprusside application improved these negative effects of cadmium stress. So, the application of 30 μM sodium nitroprusside led to an increase in total flavonoid, total phenol, soluble carbohydrate, and protein under cadmium stress conditions at 25 μM concentration.
Conclusion: The results showed that cadmium stress reduces plant growth and physiological and biochemical functions, but sodium nitroprusside application could improve cadmium's negative effects. These findings show that sodium nitroprusside can be used as an effective instrument in cadmium stress management in medicinal plants and help to improve the growth and quality of these plants. This research, in addition to enhancing our knowledge about the mechanisms of plants' response to cadmium stress, helps to analyze the effect of sodium nitroprusside in exposure to environmental life pollutants.
Improvement and breeding
- -; Masomeh Moradi; Mousa Torabi Giglou; Mahsa Ahadzadeh
Abstract
Background and objectives: Basil (Ocimum basilicum L.) is a plant from the Mint family and the genus Ocimum, which has many species, among which O. basilicum is the most useful economic species, and like other plants of the Mint family, it is a source of cyclic compounds and ...
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Background and objectives: Basil (Ocimum basilicum L.) is a plant from the Mint family and the genus Ocimum, which has many species, among which O. basilicum is the most useful economic species, and like other plants of the Mint family, it is a source of cyclic compounds and essential oil. It is also known as a rich source of phenolic compounds (especially rosmarinic acid and caffeic acid) and flavonoids. The plant's vegetative body contains essential oils. Linalool, methyl chavicol, citral, euginol, cineol, geraniol, camphor, and methyl cinnamate are important components of basil essential oil. As the most critical abiotic stress, drought stress plays a crucial role in reducing the yield of medicinal plants. It causes numerous morpho-physiological and biochemical changes in the plant. The performance of the effective substance is influenced by the plant's economic performance and environmental conditions, including drought stress. Stress effects are different at different stages of growth and development.Methodology: To investigate the effect of ascorbic acid on native O.basilicum the native population "Shahre-ray," under drought stress conditions, a factorial experiment in the form of a randomized complete block design was performed in four replications on the research farm of Horticulture Department of Mohaghegh Ardabili University in 2017. Treatments included drought stress (complete irrigation and cessation of irrigation at the beginning of reproductive growth and cessation of irrigation at 50% flowering) and ascorbic acid foliar application at four concentrations of 0.0, 0.5, 1, and 2 mM. This experiment was field operated in May 2016. Before the experiment, the bed preparation operation included plowing, disking, and leveling the ground. The plots of one meter in length and width were created. The seeds were planted in three lines with 15 cm plant spacing. 3-4 cm of rotted manure was used to cover the seeds. After determining the soil texture by the hydrometric method, the mentioned treatments were applied to stress. On the first day, irrigation was a flood, and after germination, irrigation was reduced. All traits were measured in the Physiology Laboratory after the Horticulture Science Department of the Faculty of Agricultural Sciences analyzed the data with SAS software. Also, the treatment averages were compared with Duncan's multi-range test at a probability level of 5%. Results: The results showed that with increasing drought stress intensity, total plant height, stem length, number of leaves, and plant dry weight decreased by 36.08%, 39.75%, 51.26%, and 53.80% compared to the control treatment, respectively. If ascorbic acid spraying could improve these values, the highest root length was obtained under severe stress conditions (beginning of flowering) and treatment with ascorbic acid (15.83 cm), which showed an increase of about 31.91% compared to the control treatment. Drought stress conditions increased proline and essential oil components. Chlorophyll content also decreased under severe stress. Also, by applying drought stress, in all studied traits, the highest amount of ascorbic acid treatment (concentrations of 0.5 and 1 mM) increased, and higher concentrations decreased the content of studied traits. By analyzing the essential oil of plant samples, the main compounds obtained from basil essential oil included geraniol, methyl chavicol, alphapinene, caryophyllene, citral, coupon, carvacrol, neral, linalool, and limonene. In most compounds, essential oil compounds and components were enhanced by increasing drought stress and spraying. The highest amount of essential oil in the stress condition up to the 50% flowering stage and sprayed with 2 mM ascorbic acid was obtained for methyl chavicol compound (33.76%).Conclusion: Applying ascorbic acid increased basil growth under drought stress and created resistance in the plant. Therefore, due to the lack of water resources and the great need of plants for water, it is possible to create resistance to stress in plants by spraying non-toxic and essential elements on them.
Agriculture and horticulture
H. Kiani; Sh. Khalesro; A. Mokhatssi-Bidgoli; Z. Sharifi
Abstract
Nigella sativa L. is a valuable medicinal plant that is widely used in different industries. Accumulation of compatible osmolytes is one of the common responses of plants under drought stress. To investigate the effects of irrigation regimes and biochar (resulting from the heating of cattle manure) on ...
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Nigella sativa L. is a valuable medicinal plant that is widely used in different industries. Accumulation of compatible osmolytes is one of the common responses of plants under drought stress. To investigate the effects of irrigation regimes and biochar (resulting from the heating of cattle manure) on N. sativa, a factorial experiment was conducted in a completely randomized design with three replications in the greenhouse of the Faculty of Agriculture at the University of Kurdistan in 2018. The experimental factors consisted of three drought stress levels (40, 70, and 100% of FC) and two biochar use levels (0 and 15 tons.ha-1). The ANOVA results showed that the interaction effects of drought stress and biochar were significant on hydrogen peroxide, malondialdehyde, superoxide dismutase, peroxidase, proline, soluble carbohydrates (water and ethanol soluble), and osmotic potential. Increasing the intensity of drought stress enhanced the amount of hydrogen peroxide, malondialdehyde, superoxide dismutase, peroxidase, proline, and soluble carbohydrates (water and ethanol soluble) and caused the osmotic potential to become more negative. Biochar application decreased the negative effects of drought stress so that hydrogen peroxide, malondialdehyde, superoxide dismutase, peroxidase, proline, and soluble carbohydrates (water and ethanol soluble) amounts were lower than the treatments without biochar. Overall, the present research results proved the useful and effective role of biochar in improving the physiological traits and protective osmolytes of N. sativa under drought stress.
Agriculture and horticulture
M.H. Rad; R. YazdaniBiouki; V. Soltany gerdeframarzi; N. Besharat
Abstract
To investigate the effects of irrigation water salinity (3, 6, 9, 12, and 15 dS.m-1) on morphophysiological characteristics of seedless barberry (Berberis vulgaris L.) aerial parts, an experiment was conducted using drained big pots in a completely randomized design with three replications at the central ...
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To investigate the effects of irrigation water salinity (3, 6, 9, 12, and 15 dS.m-1) on morphophysiological characteristics of seedless barberry (Berberis vulgaris L.) aerial parts, an experiment was conducted using drained big pots in a completely randomized design with three replications at the central station of National Salinity Research Center, Yazd during 2018-2021 years. The salinity levels affected the height, diameter, area, and volume of plants canopy, number of new branches, number of new basal shoots, number of leaves per plant, total leaves area, leaf area index, leaf dry weight, leaves damage percentage at high temperature, amount of total chlorophyll, chlorophylls a and b, carotenoids, proline, total sugar, leaf anthocyanins, leaf phenols, and antioxidant activity significantly (P<0.01). Based on the results, B. vulgaris tolerated the salinity stress well. Despite the growth reduction at salinity levels above 9 dS.m-1, plant physiological resistance was observed through the production of secondary osmolytes and survival under saline conditions up to 12 dS.m-1. Accordingly, in suitable barberry production habitats, it is possible to take advantage of water resources and saline soil to grow seedless barberry, especially to increase phenolics, by ture management of the root environment and control of the saturated soil extract salinity up to 12 dS.m-1.
Agriculture and horticulture
R. Rostami; B. Esmaielpour; S.A. Hosseini; G. Salimi; A. Etminan
Abstract
To investigate the effects of mycorrhizal fungi on growth characteristics, physiology, and essential oil yield of thyme (Thymus vulgaris L.) under lead (Pb) stress, a factorial experiment was conducted in a completely randomized design with three replications in the research greenhouse of University ...
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To investigate the effects of mycorrhizal fungi on growth characteristics, physiology, and essential oil yield of thyme (Thymus vulgaris L.) under lead (Pb) stress, a factorial experiment was conducted in a completely randomized design with three replications in the research greenhouse of University of Mohaghegh Ardabili (UMA) in 2018. Experimental treatments included different levels of Pb heavy metal (0, 200, and 400 ppm) and inoculation with mycorrhizal fungi (without inoculation, inoculation with Funneliformis mosseae, and Claroideoglomus etunicatum). The results showed that in comparison with the control, with increasing Pb concentration in the soil, plant height (40.56%), number of leaves (36.09%), stem dry weight (43.50%), essential oil percentage (40%), and cell membrane stability (16.14%) were significantly decreased, while proline content (51.72%) and catalase activity (45%) of the leaves increased. Inoculation of thyme with the mycorrhizal fungi was effective in increasing the vegetative indices in presence of Pb heavy metal so that both G. mosseae and G. etunicatum increased the number of leaves by 66.20 and 9.55% compared to the control, respectively. Also, inoculation with G. mosseae under severe Pb stress conditions (400 ppm) increased leaf proline content (11.49%), peroxidase enzyme activity (8.8%), chlorophyll b (21%), total chlorophyll (70.43%), carotenoids (19.6%), and essential oil percentage (55%) compared to the control. Overall, both mycorrhizal fungi were effective on alleviation of Pb toxicity effects and F. mosseae had better performance, especially in terms of morphological traits and essential oil yield. Due to the negative effects of heavy elements on human health, the recommendations to use mycorrhizal fungi to reduce the absorption of heavy metals in plants should be done with more consideration of all aspects including the plant and fungus species type and rate and pollution type.
Agriculture and horticulture
A. Abbasi Khammar; M. Moghaddam; A. Asgharzade; M. Mahmoodi Sourestani
Abstract
To study the effects of different nitrogen levels (0, 70, 140, and 210 mg l-1) on some growth, biochemical, and nutrient uptake (nitrogen, phosphorus, and potassium) characteristics and essential oil content in sage (Salvia officinalis L.) under hydroponic conditions, a pot experiment was conducted based ...
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To study the effects of different nitrogen levels (0, 70, 140, and 210 mg l-1) on some growth, biochemical, and nutrient uptake (nitrogen, phosphorus, and potassium) characteristics and essential oil content in sage (Salvia officinalis L.) under hydroponic conditions, a pot experiment was conducted based on a completely randomized design with four replications in the research greenhouse of Ferdowsi University of Mashhad in 2019. The results of means comparison showed that with increasing the nitrogen level, the plant growth characteristics increased, so that the 210 mg l-1 N treatment decreased the stem diameter, number of branches, nodes, and leaves, length of internodes, length and leaf width, fresh and stem dry weight, fresh and aerial parts dry weight, and aerial parts dry weight to root dry weight ratio by 54.19, 72.59, 39.49, 82.52, 51.42, 72.20, 71.46, 95.17, 90.31, 95.82, 92.30, and 83.46%, respectively compared to the no N application. The application of 210 mg l-1 N increased the relative content of leaf water (RWC), proline, and essential oil content by 9.57, 266.6, and 14.87% and decreased the electrolyte leakage and malondialdehyde by 30.45 and 51.51%, respectively compared to the no N application. Also, the lowest N level decreased the K, P, and N content by 32.65, 85.13, and 56.89%, respectively compared to the highest N level. The results of this experiment showed that different N levels could have different effects on the growth and essential oil content of sage. Based on the present research findings, the application of 210 mg l-1 N could be recommended for the sage cultivation due to the improving effects on the studied traits of the plant.
Agriculture and horticulture
A. Hayati; M.M. Rahimi; A. Kelidari; S.M. Hosseini
Abstract
Black cumin (Nigella sativa L.) seeds are used in the traditional medicine in many countries to prevent and treat many disorders and diseases including cough, asthma, nasal congestion, headache, toothache, intestinal worms, menstrual disorders, gastrointestinal diseases, and impotence. To study the effects ...
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Black cumin (Nigella sativa L.) seeds are used in the traditional medicine in many countries to prevent and treat many disorders and diseases including cough, asthma, nasal congestion, headache, toothache, intestinal worms, menstrual disorders, gastrointestinal diseases, and impotence. To study the effects of humic acid and iron nanochelate on the content of osmotic protective osmolites including glucose, fructose, sucrose, proline, superoxide dismutase, catalase, and peroxidase of medicinal plant black cumin under the drought stress conditions, an experiment was conducted as a split factorial based on the randomized complete block design with three treatments in three replications at the Agricultural and Natural Resources Research Station of Eqlid city during two crop years of 2018 and 2019. The main plot consisted of three levels of irrigation (50, 75, and 100% of available water) and sub-plots included humic acid (0, 250, and 500 mg l-1) and iron nanochelate (0, 1, and 2 g l-1). The results showed that the effects of irrigation, humic acid, and iron chelate treatments on the catalase, superoxide dismutase, glucose, and peroxidase content, irrigation treatments on the proline content, and irrigation and humic acid treatments on the sucrose and fructose content were significant. The content of all protective osmolites increased in the 50% drought stress treatment. The highest content of glucose, fructose, and sucrose was obtained in the 50% drought stress, 500 mg l-1 humic acid, and 2 g l-1 iron nanochelate treatment. Overall, based on the results of this experiment, the application of humic acid fertilizer (500 mg l-1) and iron nanochelate (2 g l-1) could be recommended to reduce the effects of drought stress on black cumin.
Agriculture and horticulture
P. Arvin; R. Firuzeh
Abstract
Salinity is one of the most important and common environmental stresses that affects the quantitative and qualitative yield of many plants. Fenugreek (Trigonella foenum-graecum L.) is one of the most well-known medicinal plants, which is used in the cure of many diseases due to its various effective ...
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Salinity is one of the most important and common environmental stresses that affects the quantitative and qualitative yield of many plants. Fenugreek (Trigonella foenum-graecum L.) is one of the most well-known medicinal plants, which is used in the cure of many diseases due to its various effective compounds such as trigonelline. This study was aimed at investigating the effects of salinity stress on the yield components and some physiological and biochemical characteristics of four fenugreek populations under the greenhouse conditions. The pot factorial experiment was conducted in a completely randomized design with three replications. The experimental factors included four populations (Neishabour, Shirvan, Shiraz, and Ardakan) and four salinity levels (0, 30, 60, and 90 mM). At the final stages of growth, the traits including the relative water content (RWC), number of pods per plant, number of seeds per pod, 1000-seed weight, and content of soluble sugars, proline, and trigonelline were measured in the mature plants. The salinity stress decreased the yield traits such as the number of pods per plant, number of seeds per pod, and 1000-seed weight in the all populations studied. The results showed that the salinity stress also decreased the concentration of soluble sugars and RWC, but increased the content of proline and trigonelline in the seeds. The population Shiraz was superior to the others in terms of the traits studied and showed more efficient mechanisms to tolerate the stress conditions.
Improvement and breeding
A. Barghi; A. Gholipouri
Abstract
Salinity is one of the most common abiotic stresses, which causes a high decrease in crop production. Growth regulators play an important role in plant growth and development under normal and stress conditions. To study the effects of foliar application of jasmonic acid and 24-epibrassinolide on yield ...
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Salinity is one of the most common abiotic stresses, which causes a high decrease in crop production. Growth regulators play an important role in plant growth and development under normal and stress conditions. To study the effects of foliar application of jasmonic acid and 24-epibrassinolide on yield and yield components, oil and essential oil percentage and some physiological characteristics of black cumin (Nigella sativa L.) under salinity stress conditions, a factorial experiment based on the randomized complete block design was conducted in the research greenhouse of Mohaghegh Ardabili University with three replications. The treatments included salinity at four levels (0, 5, 10 and, 15 ds.m-1 NaCl) and plant growth regulators at three levels (control, 0.1 mmol 24-epibrassinolide, and 0.5 mmol jasmonic acid). Results of mean comparisons indicated that salinity stress decreased plant yield, number of seeds per capsule, number of capsules per plant, and seed oil percentage, while significantly increased 1000-seed weight and proline content. Growth regulators also increased 1000-seed weight and seed oil percentage and decreased proline content. Chlorophylls a and b contents of the leaves decreased with increasing salinity levels, and the use of jasmonic acid and 24-epibrassinolide increased their amounts at all salinity levels. Malondialdehyde content increased with increasing salinity levels, and plant growth regulators foliar spray decreased its content at all stress levels. Besides, the percentage of seed essential oil increased with increasing salinity levels and also with plant growth regulators application at all salinity levels. It is recommended to foliar spray the plant with 24-epibrassinolide and jasmonic acid growth regulators under salinity conditions to avoid stress damages and increase black cumin essential oil, which is a very important compound in the pharmaceutical industry, as well as to enhance seed oil percentage, 1000-seed weight, and photosynthetic pigments of black cumin.
Improvement and breeding
B. Esmaielpour; M. Shiekhalipour; M. Torabi-Giglo
Abstract
Soil salinity in arid and semi-arid regions is one of the most important abiotic stresses causing negative effects on the growth and yield of medicinal plants. To investigate the effect of Zn nanoparticles foliar spray at different levels on growth characteristic, antioxidant enzymes, and essential oil ...
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Soil salinity in arid and semi-arid regions is one of the most important abiotic stresses causing negative effects on the growth and yield of medicinal plants. To investigate the effect of Zn nanoparticles foliar spray at different levels on growth characteristic, antioxidant enzymes, and essential oil yield of dragonhead (Dracocephalum moldavica L.) under salinity stress conditions, a factorial experiment was conducted in a completely randomized design with three replications in the greenhouse of Mohaghegh Ardabili University during 2018-2019. Experimental treatments included salinity stress at four levels (0, 50, 100, and 150 mM of NaCl) and foliar spray with Zn nanoparticles at three levels (0, 100, and 500 mg.l-1). Traits including plant height, aerial parts fresh and dry weight, chlorophyll, cell membrane electrolyte leakage, relative water content, proline, antioxidant enzymes, and percentage and yield of essential oil were measured. Results showed that salinity significantly decreased plant height, shoot fresh and dry weight, chlorophyll, the relative water content of leaves, and essential oil yield, and increased electrolyte leakage from cell membranes and proline content of the leaves. While nano-Zn foliar spray reduced the negative effects of salinity stress by increasing the growth and activity of antioxidant enzymes such as ascorbate peroxidase and superoxide dismutase. Treatment of 500 mg.l-1 nano-Zn caused the best-improving effect on traits including plant height, stem dry weight, chlorophyll, electrolyte leakage, antioxidant enzymes, and essential oil yield under salinity stress conditions. Therefore, the use of 500 mg.l-1 nano-Zn is recommended as a reduction of the negative effects of salinity stress in dragonhead.
A. Rahbary; H. Fatemi; B. Esmailpour
Abstract
Recently, various methods have been used to alleviate the detrimental effects of pollutants. The application of biofertilizers with respect to their positive impacts on soil characteristics and environment can be served as a suitable alternative to many of these methods. In order to investigate the two-way ...
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Recently, various methods have been used to alleviate the detrimental effects of pollutants. The application of biofertilizers with respect to their positive impacts on soil characteristics and environment can be served as a suitable alternative to many of these methods. In order to investigate the two-way effect of bacterium Pseudomonas fluorescens on plant growth, physiological and biochemical characteristics of dill (Anethum graveolens L.) under Pb stress conditions, a factorial experiment based on a completely randomized design with three replications was conducted at Mohaghegh Ardabili University. Experimental treatments included Pb stress at two levels (0 and 600 ppm) and bacterial inoculation at three levels (inoculation with Pseudomonas fluorescens strains150 and 159 separately and without inoculation (control)). The results of this study showed that the growth characteristics such as leaf number, plant height, and shoot fresh and dry weight were significantly affected by Pb contamination and shoot fresh and dry weight, leaf number and plant height decreased by 22, 31, 19 and 9%, respectively. The content of proline and carbohydrates in dill showed a significant increase under the influence of lead. Bacterial inoculation also increased the content of proline and plant carbohydrates, which was more pronounced in inoculation with strain150. The activity of antioxidant enzymes was significantly influenced by Pb contamination and bacterial inoculation. Pb increased peroxidase but decreased catalase activity, but inoculation with Pseudomonas bacteria, especially strain 150, significantly increased the activity of both enzymes. In addition, the bacteria were able to reduce the amount of Pb in dill. In general, the results of this experiment indicated that Pseudomonas bacterial inoculation was effective in alleviating the effects of Pb stress on dill via growth promotion and improving enzymatic activity.
Y. Mehrabi; M. Movahhedi Dehnavi; A. Salehi; R. Mohatashami; M. Hamidian
Abstract
In order to investigate the effects of different levels of supplementary irrigation and bio-fertilizers on some physiological traits, yield, and essential oil percentage of medicinal plant cumin (Cuminum cyminum L.), an experiment was conducted as split-plot in a randomized complete block design ...
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In order to investigate the effects of different levels of supplementary irrigation and bio-fertilizers on some physiological traits, yield, and essential oil percentage of medicinal plant cumin (Cuminum cyminum L.), an experiment was conducted as split-plot in a randomized complete block design with three replications in the research field of Kohgiluyeh and Buyer-Ahmad Agricultural and Natural Resources Research and Training Center in 2017. The main plot included supplementary irrigation (complete rainfed conditions, supplementary irrigation at 50% flowering and at the start of seed formation) and the subplot included bio-fertilizer (no phosphorus bio-fertilizer, mycorrhiza Glomus mosseae, phosphorus bio-fertilizer, and combination of mycorrhiza and phosphorus bio-fertilizer). The application of supplementary irrigation with bio-fertilizer increased the total chlorophyll and carotenoid and decreased the proline content. Phosphorus bio-fertilizer also increased catalase enzyme activity in the plant. The effects of supplementary irrigation and phosphorus bio-fertilizer on the number of umbrella per plant, plant height, 1000-seed weight and the number of seeds per umbrella were significant. The highest amount of 1000-seed weight (2.55 g), seed yield (622.4 kg ha-1), biological yield (1252 kg ha-1), and essential oil percentage (54.86%) was obtained in the mycorrhiza treatment together with the phosphorus bio-fertilizer. In general, the results showed that using phosphorus bio-fertilizer, mycorrhiza, and supplementary irrigation can improve physiological traits, yield, and essential oil of cumin under rainfed conditions.
M. Salmalian; A. Ghasemnejad; K. Mashayekhi
Abstract
Using stimulants is an efficient way to increase the production of secondary metabolites of medicinal plants under in vivo and in vitro conditions. The present study aimed to investigate the effect of NaCl (0 and 50 mM), salicylic acid, and methyl jasmonate (each in 0 and 100 μM) in solid and liquid ...
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Using stimulants is an efficient way to increase the production of secondary metabolites of medicinal plants under in vivo and in vitro conditions. The present study aimed to investigate the effect of NaCl (0 and 50 mM), salicylic acid, and methyl jasmonate (each in 0 and 100 μM) in solid and liquid culture media on the biochemical properties and phenylalanine ammonia-lyase (PAL) activity of stevia callus under in vitro conditions. This study was conducted in a completely randomized design with a two-factor factorial arrangement in four replications. The stimuli used, culture medium and their interactions had a significant effect on the measured traits. The highest amount of phenol and flavonoid production was observed in salicylic acid 100 + salinity 50 and salinity 50 treatments in solid culture medium. Treatments including salinity 50, salicylic acid 100 + salinity 50 and methyl jasmonate 100 + salinity 50 in the solid medium increased PAL enzyme activity compared to other treatments. PAL enzyme, phenol and flavonoid were positively correlated each other. The 50 mM salinity treatment also increased proline amino acid content. Therefore, in order to improve the production of secondary compounds such as phenol, flavonoids and also PAL enzyme activity in stevia, a combination of salicylic acid (100 μM) and salinity (50 mM) is recommended under solid culture medium conditions.
B. Esmaielpour; H. Fatemi; M. Moradi
Abstract
Drought stress, as one of the most important abiotic stresses, plays an important role in decreasing the yield of medicinal plants. In order to investigate the effect of nitric oxide on morphophysiological and biochemical characteristics of basil (Ocimum basilicum L.), the native population "Shahre-ray", ...
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Drought stress, as one of the most important abiotic stresses, plays an important role in decreasing the yield of medicinal plants. In order to investigate the effect of nitric oxide on morphophysiological and biochemical characteristics of basil (Ocimum basilicum L.), the native population "Shahre-ray", a factorial experiment was conducted in a completely randomized design under drought stress conditions with three replications in the research greenhouse of Mohaghegh Ardabili University in 2017. Experimental factors included drought stress at three levels of complete irrigation (drip irrigation at three-day intervals throughout the growing season) and complete stop of irrigation at early flowering stage (60 days after planting at 10-12 leaf stage) and 50% flowering (75 days after planting at 14-15 leaf stage) and nitric oxide spray with sodium nitroprusside at four concentration levels of zero (leaf spray with distilled water), 0.5, 1, and 2 mM. The foliar application was carried out from the eight-leaf stage of the plant, with intervals of two weeks to four times. Results showed that stopping irrigation at both mentioned growth stages significantly reduced plant height, plant dry weight, chlorophylls a and b, total chlorophyll, carotenoid, and relative water content, and significantly increased electrolyte leakage rate, leaf proline content, and essential oil percentage. Foliar application of 2 mM nitric oxide significantly increased plant growth under irrigation interruption, especially at 50% flowering. Increasing the concentration of nitric oxide produced the highest essential oil percentage (1.4%) at the early flowering stage under irrigation interruption conditions and significantly increased the content of essential oil components including methyl chavicol, linalool, geranial, geraniol, α-pinene, β-pinene, and myrcene. In general, the results showed that foliar application of nitric oxide at 50% flowering stage under irrigation interruption improved the growth of basil and increased the percentage and components of essential oil via osmotic adjustment, preventing chlorophyll degradation and maintenance of leaf water content.
A. Mazarie; S.M. Mousavi-nik; A. Ghanbari; L. Fahmideh
Abstract
Water deficit stress is a major environmental limiting factor for plant growth and crop productivity. In present investigation, to study the effects of jasmonic acid on reducing the damage caused by drought on growth parameters, some physiological and antioxidant responses on Salvia officinalis L., a ...
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Water deficit stress is a major environmental limiting factor for plant growth and crop productivity. In present investigation, to study the effects of jasmonic acid on reducing the damage caused by drought on growth parameters, some physiological and antioxidant responses on Salvia officinalis L., a factorial experiment in a completely randomized design with three replications was conducted at the University of Zabol. The experimental treatments included drought stress (irrigated in field capacity, depletion of soil water content up to 50% and 75% of FC condition) and foliar jasmonic acid spray (0, 75 and 150 mg.l-1). The results showed that spraying with a concentration of 150 (mg. l-1) jasmonic acid under drought stress increased the height (% 10.02), fresh and dry weight (27.88% and 12.81%), relative water content (21.04%) and chlorophyll a and b content (12.15% and 10.34%). The highest phenolic content (34.13 mg-1fw), proline concentration (5.52 mg-1fw), essential oil yield (2.1 mg-1fw) and the activities of peroxidase (3.15 mg-1fw) and guaiacol peroxidase (0.76 mg-1fw) were obtained in plants sprayed with 150mg.l-1 jasmonic acidand in depletion of soil water content up to 75% of FC. On the other hand, the highest ascorbate peroxidase (0.76 mg-1fw), superoxide dismutase (5.64 mg-1fw) and catalase (5.12 mg-1fw), were obtained in plants sprayed with 150 mg -1 jasmonic acid under drought stress (depletion of soil water content up to 75 and 50% FC). Based on our results, it seemed that Jasmonic acid, with increasing antioxidant defense and accumulation of osmotic regulators (such as proline), reduced the oxidative stress in plants under drought stress. Moreover, maintaining the relative water content and photosynthetic pigment improved growth conditions of sage plants in drought conditions.
Gh. Salimi; M. Feizian; N. Aliasgharzad
Abstract
Drought stress causes reduction in growth and changes in biochemical indices of plants. In order to investigate the effect of arbuscular mycorrhizal fungi and selenium on reduction the detrimental effects of drought stress in Moldavian balm (Dracocephalum moldavica L.), a split plot-factorial experiment ...
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Drought stress causes reduction in growth and changes in biochemical indices of plants. In order to investigate the effect of arbuscular mycorrhizal fungi and selenium on reduction the detrimental effects of drought stress in Moldavian balm (Dracocephalum moldavica L.), a split plot-factorial experiment based on complete randomized block design with four replications was carried out under greenhouse condition. The main factor was three levels of drought [control, 0.75 Maximum Allowable Depletion (MAD) and 0.5 MAD] and sub factors included selenium at three levels (0, 100 μg per plant and 200 μg per plant) and inoculation with mycorrhizal fungi in two levels (non-inoculated as control and Glomus.verciforme). The results indicated that drought stress reduced height, dry weight and leaf area of plants. The lowest and highest value for all of these characteristics was obtained at 0.75 MAD and without drought stress, respectively. In non-stress condition, height, dry weight and leaf area of plants obtained from inoculation with mycorrhizal fungus and selenium were significantly higher than those of control. In all levels of drought stress, the content of catalase and peroxidase enzymes in plants inoculated with mycorrhizal fungus and selenium was significantly higher than that of control. The lowest content of catalase enzyme (25.06) was obtained in control and lowest content of peroxidase (14.81) was in the treatment with mycorrhizal fungus and selenium under 0.75 MAD drought stress. The highest content of catalase enzyme (53.62) was in inoculation with mycorrhizal fungus and 200μg selenium without stress, and the highest content of peroxidase (31.59) was obtained in 0.5 MAD stress and inoculation with mycorrhizal fungus and 200 μg selenium. Also, in condition of inoculation with fungus and selenium, the content of proline and MDA increased about 1 to 1.5 folds and about 1.3 to 1.5 folds, respectively, more than the control. Results showed that the presence of mycorrhiza and selenium in drought stress condition had a positive effect on growth and biochemical indices studied.
A. Mazaraei; A.R. Sirousmehr; Z. Babaei
Abstract
Drought stress, temporally or permanently, is a more limiting factor in growth and distribution of vegetation cover than other environmental factors. In order to study the effects of vesicular arbuscular mycorrhizal and drought stress on growth and yield of Milk thistle (Silybum marianum (L.) Gaertn.), a ...
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Drought stress, temporally or permanently, is a more limiting factor in growth and distribution of vegetation cover than other environmental factors. In order to study the effects of vesicular arbuscular mycorrhizal and drought stress on growth and yield of Milk thistle (Silybum marianum (L.) Gaertn.), a pot experiment was performed as factorial based on completely randomized design in three replications in the research greenhouse of Chahnimeh at the University of Zabol. Drought stress consisted of two levels including %60 and %30 of field capacity and full irrigation as control treatment. Three mycorrhizal fungi including Glomus mosseae, Glomus versiformis, and Glomus intraradices were investigated. The results showed that after starting of drought stress, vegetative characteristics such as number of capituls, number of seeds in capitul, 1000 seeds weight, leaf number and area, root length, number of minor branches, plant height, and dry weight of leaf, stem and root, significantly decreased with increasing drought stress. RWC of leaf was intensely affected by drought and decreased from 77.3 in control treatment to 57.01 in 30% of field capacity irrigation treatment. In addition, with increasing drought stress, the amount of phosphorus in leaves decreased and the amount of potassium increased. Osmotic adjustment in Milk thistle was increased in response to drought stress and leaf proline content increased (the highest 0.13 mg/g tissue in 30% of field capacity treatment); however, silimarin content decreased from 16.35 in full irrigation to 10.24 in 30% of field capacity treatment. Inoculation with VAM significantly increased vegetative indices, silimarin content (the highest in G. mosseae application and the lowest in control), plant RWC, and leaf content of P and K under drought stress conditions compared to uninoculated plants; however, the leaf proline content was low. In general, application of mycorrhizae fungi increased drought stress resistance in Milk thistle.
M. Ebrahimi; Gh.R. Zamani; Z. Alizadeh
Abstract
As an important medicinal plant in some industries such as pharmaceutical industry, the antioxidant capacity of pot marigold (Calendula officinalis L.) in conferring drought stress, as well as physiological and yield-related traits were studied. A complete randomized block design with three replications ...
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As an important medicinal plant in some industries such as pharmaceutical industry, the antioxidant capacity of pot marigold (Calendula officinalis L.) in conferring drought stress, as well as physiological and yield-related traits were studied. A complete randomized block design with three replications was carried out in the research greenhouse of Birjand University during 2014, 2015. Four levels of drought stress (including 80, 60, 40 and 20 percent of the available soil water content) and two plant types (medicinal and ornamental) were considered in this study. According to the results, with increasing drought severity, APX activity decreased and SOD and CAT activity initially increased and then decreased. Over accumulation of reactive oxygen species along with inefficiency of the antioxidant system had possibly resulted in the impaired enzymatic antioxidant efficiency in the highest level of drought stress. Proline content increased along with increasing drought intensity, so that it was up to fourfold in the highest level of drought stress, compared to non-stressed control. Although proline is an antioxidant compound, no relationship was found between proline accumulation with antioxidant enzymes. Carotenoids, chlorophyll content and chlorophyll index all decrease, and MDA content increased with increasing drought intensity, as a result of damages to chloroplast membranes. Reduced photochemical efficiency of photosystem II was another consequence of intensified water deficit. Drought stress also negatively affected yield related traits, so that dry weight (27%), height (32%), number of lateral branches (33%) and flowers (50%) and flower yield (60%) decreased. We also found that medicinal pot marigold (824.3 kg.ha-1) produced more flower than ornamental one (654.9 kg.ha-1). In conclusion, we found that enzymatic antioxidant system of pot marigold conferred a suitable ability to reduce adverse effects of drought-induced oxidative stress. Hence, increasing pot marigold’s antioxidant activity could result in increasing its physiological resistant to drought stress and consequently improves its yield components performance.
